Period start without meds 1st time in life!

Okay. Hello! I am 29 & was diagnosed with PCOS when I was 17. I have NEVER in my life had a period that wasn't medically induced, either with Provera or birth control. I have been living a ketogenic lifestyle since August & I have lost about 86lbs since. I went back on birth control for cysts but had extremely heavy bleeding that required a d & c to stop. That was in October. Had a "normal" period in November while on birth control but had the heavy bleeding in December, so I stopped taking the birth control completely. I had a period in January without birth control for the first time but thought it might be a just the birth control still being in my system. I was due for a period around valentine's day but it didn't come so I was prepared to go see my OBGYN but low & behold on March 2nd I started & had a completely normal period! Lasted 5 days with only one day of "heavy" bleeding! I have started using opks twice a day to see if I can catch a surge & I've started using a bbt just to see. I am in shock. Anyone else have this happen & became pregnant on their own? I do not expect to become pregnant this cycle, just trying to get back into the swing of testing & adding in bbt. Thanks in advance for any info!