A polyp?

Went to RE's today. There was a small black circle in the uterus. He said it was a polyp. He said nothing to be be too too concerned about but it has to be gone before we start injections again. The he threw me for a loop when he asked me "Are your breasts tender" and "Were your breasts tender?" I said they weren't tender now but they were a little earlier in the week. Now I am confused as EVER. He made no mention as to if it could be a pregnancy (gestational sac) he just told me to call him when my period arrives. I have been thinking and researching polyps, and 4 week gestational sacs and this is what I am thinking. Either it is a small polyp and it hopefully it will be gone by the time my cycle starts so we can start our meds again. Or, I am pregnant and Dr. Hecht of course does not want to give me any false hope that I am or will stay pregnant- plus if I was pregnant he wouldn't be seeing me/taking care of me since I haven't been seeing him for treatments- I would be going to my normal midwife and that's why he didn't suggest getting any blood work or didn't mention anything about calling if I DON'T get a period. Or lastly, maybe I was pregnant and it turned into a polyp??? BUT When I did research about polyps and from what Scott told me- polyps have stalks with a bigger top (like a tree). The ultrasound picture was an exact circle. I found a picture of a sonogram of a gestational sac at four weeks- it is exactly what I saw on the screen this morning. Yes- I'm freakin out. I think I am going to buy a pregnancy test today after work. If it is negative I still know I am going to start fertility treatments again (if the "polyp" is gone) so I have something to make me feel better and fall back on.
My gut is telling me that Dr. Hecht just said polyp because he didn't want me to get excited about an extremely early possible pregnancy. I'm really trying to stay calm. (yeah right!!!)