I had my cycle on Dec. 16, it lasted 4 days. Had sex Dec. 14 & 15. Had sex again on Dec. 20th. Now I have been experiencing bloating, lower abdominal discomfort, fatigue, nausea. I have also been doing IVF. One cycle as of Dec. 2 it didn't take. I am wondering if I could have gotten pregnant on my own? My cycle is not due until Jan. 15th.
I don't want to get my hopes up, but there is definitely something going on with my uterus.

It could be possible. I got pregnant right after I got off my period... some people experience symptoms earlier than others... I would wait until your next period is due and if you are late I would go get a pregnancy test done.