Has anybody had a BFP but NOT been pregnant?

[MamaGothel]

Hello
I have 2 children already and got my BFP yesterday after 3 years of not trying not preventing, but I'm worried it might not be a true pregnancy.
I have PCOS and have already missed 2 periods, even though I am usually regular with a roughly 34 day cycle. I was testing negative up until about a week ago. When i missed my period, I was worried that my PCOS was getting worse as I have put on weight and was growing a lot of facial hair.
Now I have researched false positives and I have seen that a corpus luteum cyst could cause this and I'm worried that I could be getting my hopes up for nothing.
I was wondering if anybody has experience of a false positive?
I'm going to try to make a doctors appointment tomorrow, I have also had an ectopic pregnancy in the past so I will need an early scan to rule that out.

False positives are pretty impossible as hcg is only produced when an embryo implants into the body.....a corpus Luteum cyst can't produce hcg however what you can get is a blighted ovum where the egg implants but doesn't grow and so a sac forms but with no baby and the corpus luteum cyst behaves like you are pregnant

Thanks for the reply- I suppose the only way to tell would be a scan? I'm not sure why I'm so anxious about this its the unusual missed period that is making me question the positive. And having waited so long for it.