At what point do I start believing negative tests?

Over the past few months I've been a bundle of hormones. Off mirena for 3 weeks, now I'm one week into a 3 month pill. My last time having unprotected sex was 12/20 and he did not finish in me. Because of mirena and now the pill I haven't had a period in months. I'm obsessively taking pregnancy tests almost every morning because if im pregnant I obviously need to know. I just feel so weird with could be pregnancy symptoms that I start to convince myself I am pregnant. Also- I had a blood pregnancy test done about 20 days after sex and it was negative. Do I need to calm down and stop taking tests at this point? I'm so paranoid!