Pregnancy test is positive then negative in hospital

I called my gyneacologist yesterday and asked if they could help me because I had the feeling they gave me a wrond diagnosis. They said i had bacterial vaginosis. So by the end of the day I went to the hosptial to ask if i have a vaginal thrush which I ended up having.

So I had to do a urine test which was quite concentrated and I was told I was pregnant and that I had a UTI. I then had to do another urine test and the test ended up negative without a UTI. In the concentrated urine they tested 3 times positive and in the second urine one time negative.

So now I am really scared.

I told the Doctor i took plan b around the 20th of june. My last period was june 10th till june 13th.
It’s 9 days since plan b and the Doctor said it was unlikely that I‘m pregnant and that it could be a false positive.

According to flo i was fertile from june 19th till june 25th.

So should I wait it out till I get my period on july 8th next week and test again? I feel like my gyno didnt take me seriously and also she told me last time that if I don’t take the pill and end up getting pregnant, that she hopes i keep the baby. And in the worst case I don’t want to keep it as I have no financial resources to take care of it.

Has anyone been through something similar? Like habe you gotten a positive test a week before the period but then it Ended up negative?