??? I don't know.

I had a home pregnancy test done two months after my last sexual activity it was negative.
A month later I took a blood test it was negative.
The following month I've been giving meds but my period still didn't make it.
It's been five months now. I went to the gyno and he did a pelvic exam and even rubbed the apparatus atop my stomach and found nothing.

What could it be?