Anyone had their period and been pregnant?

December was our first month TTC. I was using OPKs and Preseed. I got a positive opk on CD 18! I used HPTs on DPO 8, 10, and 12. All of them were BFNs. AF showed up on 12/31 as expected. But it only lasted 2 days (5 is my average) and it was a lot lighter than normal. The past few days I have been experiencing nausea and increased appetite and urination.

Has anyone else experienced this? Is it possible to have your period and still be pregnant? I haven’t tested yet because I ran out of tests. I haven’t bought any because I wanted to see what you guys think before spending the money.