TTC and just came off birth control - could I be pregnant already?

My husband and I decided we were ready for a baby. I stopped taking my bcp Oct. 5 (with the last active pill). I started my period on Oct. 8. It lasted about three days. At first we used protection but figured it would take awhile to actually conceive so we stopped. I had a very light period off and on Oct. 20 and 21 (sorry for tmi but it was brown). I have been exhausted lately but I hadn't been running for a few weeks and assumed that was the reason. Within the last few days I have been dizzy off and on and yesterday I was nauseous from lunch time until I went to bed. Today I've been dizzy and nauseous on and off also.

I don't know when I am supposed to start my period again (just finished seasonale so I was only getting 4 a year to begin with). I also had endometriosis removed twice and my dr. questioned whether I would be able to have children or not.

Could it be possible that I am pregnant? I'm not sure how to figure out the timing.