What female health problems could cause a false positive on an otc pregnancy test?

I'm not having a scare - it's for deus ex machina in a story I'm writing.What female health problems could cause a false positive on an otc pregnancy test?
Some tumors in women will express hCG, which is the hormone pregnancy tests look for. Also, a woman with a hydatiform mole will have loads of hCG in her blood stream. A hydatiform mole forms from an implanted zygote with incorrect DNA, due to a number of possible errors that could have occured in the fertilization process and the final meiotic division of the ovum. The zygote will go on to form the trophoblastic cells that make hCG, but not the embryo. There may be other conditions, but those are the only two I'm aware of.What female health problems could cause a false positive on an otc pregnancy test?
there are no problems in women taht would cause that, only testicular cancer in men will cause a positive pregnancy test...