Well with the strips it's hard to know since they are reporting inconsistent results. The 1:1 dilution showed >10 ppm which means the FC would be >20 ppm, but the 1:2 dilution showed 5 ppm which means the FC would be 15 ppm. The bigger problem is that you never added any CYA to the water so the chlorine is not moderated in its strength. And as you pointed out, the FC level may have been higher before you tested it.
You should ask a doctor about the health effects for you and your baby and you can tell him/her you may have been exposed to 20 ppm FC chlorine with no Cyanuric Acid to moderate its strength. Odds are they'll say they aren't sure or there's nothing to be done about it, but it would not hurt to ask. Let him/her know that the chlorine may have created chloroform in your nose, throat, and skin (see below).
In practice what happens with chlorine that you breathe is that it combines with chemicals in your mucous membranes so chlorine itself wouldn't get to your baby. The issue is that the chlorinated organics that are produced can get into your bloodstream if the chlorine reacted with organics that were volatile and entered into your lungs or that were created in skin and had dermal absorption.
This EPA document says the following with regard to chlorine exposure, though note that the quantities are referring to chlorine gas and are much higher than what you were exposed to in the air which was more likely to be hypochlorous acid (unless your pH was very low):
Chlorine is a primary irritant to the mucous membranes of the eyes, nose, and throat and to the linings of the entire respiratory tract (Stokinger 1982).
Usually chlorine exposure would be irritating to your eyes, nose, or throat. The fact that you instead have a feeling like having a hangover indicates to me that this isn't a direct effect from chlorine but rather an effect from chlorine combined with ammonia or some organic. Chloroform exposure for some people results in the feeling like a hangover (see
this EPA link regarding symptoms of "dizziness, headache, tiredness, and other effects"). Chloroform is produced when chlorine reacts with citric acid and organics with methyl ketone groups. So my best guess is that your exposure to chlorine created, among other things, chloroform and this was the source of your hangover symptoms. Unfortunately, chloroform is both volatile and absorbs through the skin (though in your case was likely created in your nose, throat, and skin), gets into your bloodstream, and can even cross the blood/brain barrier which is why you can get hangover-like symptoms.
Unfortunately, as noted in
this book (and many other sources), chloroform also crosses the blood/placenta barrier. In fact, both chloroform and ether were early anesthetics but they weren't good ones because the concentration needed to make one unconscious (1500-30,000 ppm for chloroform) is dangerously close to the level that will kill you (40,000 ppm for chloroform) and there is also variation among people. Many people died from early use of anesthetics, but eventually dosages were better controlled (via an inhaler) and then there were observations of babies born to mothers anesthetized by chloroform during childbirth and some effects were noted (babies not kicking or moving as much -- basically lethargic but such effects being temporary). Note that this is a rather high level of chloroform we are talking about.
So the possibly good news is that while your symptoms might be from chloroform produced from chlorine reacting with organics in your body and that some chloroform may have reached your baby, odds are that the effects on your baby were less than they were on you. The other good news is that chloroform is removed from the body relatively quickly (mostly through exhalation) so the effects are short-term.
To put you at ease with respect to more normal levels of chlorine in pools, if I assume that you were exposed to at least 15 ppm FC with no CYA, that level is around 375 times higher than the active chlorine amount in pools operating at the minimum FC/CYA level for SWG pools. It's also 25 times higher than the regular SLAM level. And that assumes the 15 ppm FC assumption is correct; the FC level during your exposure may have been even higher and I suspect it probably was given the effects.
By the way, commercial/public pools not using CYA (such as many indoor pools with 1 ppm FC) have around 25 times higher active chlorine levels compared to the minimum FC/CYA levels that we recommend for SWG pools.