I’m scared this is a cryptic pregnancy

hello, so yeah I’m scared that I may be having a cryptic pregnancy. so the last time I had sex was a month and a half ago. We did use protection but for less than 3 minutes we did it raw. I took a plan b pill the day after, but I didn’t need to because I had ovulated a week before. I also got my period around the same time I was expecting it and it was normal and everything, however my recent period was not very normal. It was lighter than usual. So now I’m confused because the period I had after sex it was normal and this last one was not. I took a pregnancy test as well and came out negative. I have bad anxiety so this is making it worse, I have been having a little abdominal pain and today I am experiencing nausea. So I’m not sure what those mean, I’m really scared I may be having a cryptic pregnancy, please help!