HELP! Period 5 days late

My partner and I have had sex maybe ten times since my last cycle. We used condoms AND the pullout method everytime. The only thing that has me worried is that his condom was falling off as he ejaculated one of the times. He ejaculated into the condom so it wouldn't have gotten inside of me. I'm five days late and I'm stressing myself out! I've taken four pregnancy tests. 3 of them came out negative and the other one didn't work. I have tender breasts and mild cramps here and there but I still haven't started. Any ideas or input?