What could be happening?

on the 27th of March I finished my period and on the 29th I had unprotected sex. The guy said he pulled out but I'm not sure how it feels and a day after I started to feel sick. I still have a fluttery feeling in my stomach but I'm not sure if that means I could be pregnant or What. one of the apps I use to track my period says I ovulated during that time but I'm just not sure how that works. some one help! oh and like two days ago when I wiped there was light red blood and there's been a lot of discharge