Someone help me please!!!!!!!!!!!

About a month ago I had sex with my bf and I got really paranoid so I took a test 3 weeks after having sex. The sex lasted like 60 seconds and he didn’t cum but he didn’t have a condom so just to be sure I tested 2 times and they both came out negative. He told me Idk why I’m worrying and stressing cuz he wasn’t even close to cumming and it was the shortest amount of time before I stopped him cuz I knew it was a bad idea. Basically I have been stressing because I haven’t gotten my period and this app says it’s 7 days late now. I took the test when it said I was like 3 days late and they both came out negative . I still haven’t started my period but I also have been stressing and drinking alcohol more than normal and I’ve heard that can delay your period. Im getting on birth control in 2 days and I know nothing about what that does to your cycle and if I were to test would it be accurate. Anyways all my friends are telling me I’m perfectly fine and to stop stressing. Should I take a test before I get on birth control? What do I do? Am I just freaking myself out ??