False Positive Pregnancy tests?

Je

So I have severe PCOS and do not menstruated. 14.5 months ago I gave birth to two beautiful twin girls from An IUI with Femara. However since then I have had multiple false positive at home pregnancy tests here and there from all different brands. It’s gone as far as me having to go to the dr to get blood tests because I wasn’t sure (both came back with 0 hcg so I know that’s not what’s triggering it) i can only guess it’s my high LH that’s triggering the test? I didn’t even know this was possible? Has anyone else had this happen or have a dr that has said this can happen? My doctor is baffled.