Recurring petechiae with two normal cbc's? What to do from here?

19, female. Only take tylenol.

Back in September I noticed some petechiae on my legs. It was there for about a week before I googled what it could be. Immediately I went to go get a blood test done, and my doctor did the blanch test and everything. Anyways, 5 minutes later I got my results back and everything was normal. After about a week, the petechiae didn't fade so I went back for another CBC w/ diff and liver function, and that came back normal too. My platelets were 299 thousand, and I know that petechiae affects platelets.Anyways, I'm really reassured that I had two normal blood tests, which rule out all the serious stuff. If it were sepsis or meningitis I'd be dead by now. The petechiae came back and I'm really unsure about this now... there's a small patch on my chest, but I was scratching my chest the day before so I don't know. However, I don't scratch my legs, yet they're still there. Should I possibly look into a platelet function disorder in the future? Like von Willebrand's? My mom and I get small random bruises sometimes and we both have heavy periods. But I'm not really sure at this point on what to do. My doctor knows I have bad health anxiety, but petechiae obviously isn't a symptom of health anxiety lol. I've been stressed about this for a week now and was told another CBC isn't gonna get me anywhere because it was already normal when the petechiae first showed up. Any advice?