Pregnancy?

Khy
So my boyfriend and I are very sexually active. We've had a pregnancy scare before because my period was so late, but we thought t was just because I wasn't used to it. It came and it was all good, and we got smart and used condoms. Well we keep trying different brands and they all keep breaking on us and it really sucks, so he just started pulling out a minute or two before he came, and I kept telling him Precum could get us pregant and we just have to keep working for it, but he insited were safe... 
Now its at the point where last month my period was about 3 weeks late, and when it did come it was rusty brown and not as it usually was, and lasted longer too. I took two pregnancy tests, both were negative. Now it's a week or so before my next period, but I'm having common symptoms. My head hurts, my nipples hurt, I'm constantly tired, and I feel sick in my stomach without it hurting. He thinks we're fine, but I'm not so sure... Especially since I took two tests. We've also had sex after so that could be a game changer, but i dont know what to do... 
Has this happened to any of you? Or do you have any suggestions?