Is it possible to have sex a day after your period ends and to fall pregnant? My periods stopped last Tuesday, had unprotected sex on Wednesday and every day since then. I've been feeling dizzy, nauseous, hungry, constipated but farting and burping alot, and so tired. Just not myself. What do you think? I'm also on the pill but haven't been taking it correctly.. Do I continue to take it? I'm worried.