Is it possible? SORRY SO ITS LONG LOL

So AF is due today but not really having any signs (cramps and pain in my hips are usually an indicator) BUT I had woke up with a headache and feeling queasy then me and my husband went to my mother in laws house and I threw up as soon as we got there. I tried some ginger ale it helped a little just enough for me to try to eat some salmon. As soon as I ate it the nausea Came back again. My mother in law gave me some benadryl in case I might had eaten something that had gluten in it as I have celiacs and the benadryl helps with some of the symptoms. I passed out in the car because I wasn't feeling well I woke up by time we got home and came in and took a bath I had started to feel better. So I grabbed some mashed potatoes (you can't get more bland than that right!?) ate those and drank me a coke then all of a sudden I'm puking again!! Now that I have thrown everything up again I feel fine. I have had a bit of a headache all day but not like a migraine so IDK what's going on. We did have sex with condoms on the day of ovulation and without the day after ovulation so IDK of there could still be a chance of me getting pregnant. I was just wandering if anyone has had this around 4 weeks pregnant. We just had a chemical last month so I am unsure of if I can get pregnant again so soon.