Did my IUI work?!

I had IUI#2 in mid-November but had my period start 10 days later. I was super crampy and had moderate flow. We TTC around my ovulation two weeks ago 12/22 and went back to my doctor for a “what’s next talk” on 1/2. He wants me to try IVF or InvoCell. I was supposed to start my period on Friday and felt bad cramps for a few hours and a little spotting but never started. Maybe implantation?! Today I took a test and got a faint line!! I have NEVER gotten a faint second line. I am going to retest in the morning and go to my doctor. I think I am pregnant!!! Wow, after two years of TTC and 2 IUI’s. My question is: did I get pregnant with the IUI and have a period or did I get pregnant in December? I hope I can confirm with the doctor tomorrow!