Pregnancy Question

Hi. I am new here and could use some advice. In the end she will have to go to the doctor to know for sure if she is pregnant but this will help me understand where I am at:

the girl i'm dating has had her period all the time in the last few months. She is irregular.

We have had unprotected sex a lot of the time, though I never stayed in. She was on the pill for several months. She even has taken the morning after pill a few times. The last time she took it was in september. (the condom broke. And she did have her period. ) and we used a foam cream which is supposed to prevent pregnancy. Again, while she was wearing the cream, I didn't stay in.

She had her period on 10/18/05, which was her 25th day. She said it was a light period, meaning not a lot of blood. It is now the 11/17/05 and she has not had it yet. She says she has a little back pain, which she said came from eating a lot tonight because of the stress, but no other symptoms. No nausea, no sensitivity in her breasts, no headaches, no tiredness, no morning sickness, no constant hunger, nothing. She had strong cramps a few days ago and now they have become less. She has been stressed out a lot over the last week.

I am getting mixed signs from here, obviously, as to whether or not she might be pregnant. I read that it is possible for her to have her period or the apperance of a period even if she might be pregnant, which would explain the light bleeding last month. But the large amount of stress she has had might explain why she hasn't had her period.

Best guess: is she pregnant?