I'm a little worried..

My boyfriend and I are serious. We had sex everyday the week of my ovulation without any kind of perfection, (which wasn't very smart) anyways, he didn't cum inside me but he always had a whole lot of pre cum. my ovulation day was July 27th and we had sex multiple times. I took a test because I've been cramping really bad for a few days, it just feels like my stomach is stretching on both sides and my boobs are really sore. All the tests came up negative but something still doesn't feel right. I scheduled a appointment and they said its to soon to tell and I could still be conceiving if I am. So I have to wait, what else could I do. it makes me really nervous and my anxiety is through the roof. Just to top it all off we just found out my sister is 8 weeks pregnant.