Two questions for chicks here

Hi ladies. This is my first time posting here but I have two questions just to kill two birds with one stone. Ok first off I haven't had my period since may 17th. I took a pregnancy test and I'm not pregnant I've had unprotected sex for six months now and I am beginning to think I can't get pregnant (not that I am trying) but its weird. I know this may sound stupid but if a guys ejaculates inside you can it mess up your period? I know I'm 21 an that sounds dumb as hell but idk I'm not asking my mom. Okay second question is lately everyone says I've gotten fat. I've been married for 6 months and I wet from 135 to 170. I am short and my ass is getting so huge I don't have a gut and it's mainly thighs but it makes me feel gross. I've quit eating bc of it. And I started making myself throw up after big meals bc I'm scared of getting bigger I am in a ten in pants I feel so ugly what do I do?