Is my girlfriend pregnant??

[Mo_230]

My girlfriend and I had unprotected vaginal sex exactly 6 weeks ago from today and I ejaculated inside. For some background info she started the depo shot in May and took her 2nd shot a week late in September. Mind you ever since she was on it her period has been irregular, comes at different times and it stays for around 2 weeks give or take.

Anyway, after we had sex her period started 8 days later, which was 4 days after her expected period date, her period lasted 12 days and then she had light spotting for another week after it ended.

We also had unprotected sex 11 days ago but I only agreed because she was 6 days away from expecting her period for the month of December and she also took an ovulation test a few minutes prior to sex which came back negative. Her period is now 4 days late which has me worried.  

I think her depo shot isn’t as effective because she was late taking it and I might be paranoid because of my ejaculation in her from the first encounter.

My question is, can she be pregnant from the encounter 6 weeks ago? Or the recent one?

[specialmom]

Well, some time passed. I'm guessing she isn't/wasn't pregnant. Is there an update?