I'm sooooo confused!!!

Backstory: I got my Mirena IUD taken out on Dec 22, I didn't get my period in the first 4 weeks, so I started using OPKs.

I ovulated Feb 2nd and then had my first period Feb 15-19, so I started that period 13 DPO.

I continued using OPKs and ovulated March 2nd, so now I am 21DPO, with no period AND I had a negative pregnancy test this morning (Clinical Guard).

Did I just skip a period? Should I get a different test? Keep taking pregnancy tests? Should I start using OPKs right now in my cycle? Is it possible to ovulate twice in one cycle? Help!!!