What to do?

I have had the strangest cycle ever. My last period was in June. I am currently ten days late (I did take a test but it was negative.) A week or so ago I passed small clots for a few days.m - super tiny like pencil eraser sized. When my period was supposed to start I got really super cranky - like I should suddenly have a crime scene in my pants - nothing. I also had a sharp pain on my right side and I instantly thought "cyst, it's a cyst."

I had surgery in June and missed some doses of my pill, but I either took it when I realized or doubled up (it's hard to remember in a zombie mode of pain killers.)

Today I went to the doctor. They did a pregnancy blood test and tests for possible STIs (I'm not thinking it is the STI route, but better safe than sorry). I'm more concerned about the pregnancy test. If it is positive, this was not planned at all. I've only been with my BF for a few months, and this would be super fast.

We talked about kids before we started dating, but this is something that is long off. I'm scared of how I'm going to tell him if that is the case. I don't want him to think I did it on purpose, I didn't. Any advice would be appreciated - how to talk about it or if you have any idea about what those random clots would be (I saw a Nurse Practitioner as my doctor was booked and she didn't seem concerned about that)