What should I do?

So I'm a bit confused. Hopefully someone can help me!! So I'm usually on time, always have been besides the time I was on depo & nexplanon then I had no periods. I been off any type of BC and my cycles are usually short like 25 days and last 3 to 4 days & well I'm on day 37 of my cycle, I took a pregnancy test Sunday and it came out negative and still no period. I'm not sure if maybe it was a bad test or what? I got just a cheap off brand. Im a bit scared because I don't wanna take another and see it come negative because ill be devastated that I got my hopes up. HELP.