It's that time of month for my girlfriend, yesterday she thought she was just getting her period. She was at work and it got so bad, she was in so much pain and body ache and nausea that she went home early from work. At home she threw up and was in horrible pain. Today she is a little better, just tired and achy. She said she never has it like this. We have been together about 2 months and have mostly protected sex average 3 to 4 times a week. When unprotected I pull out before, and we have gotten the plan b pill a few times when we weren't totally sure if we were in the clear or not. This last weekend she took a pill. The pill is really bad hormonally for her so neither of us like to go that route. I'm wondering if that pill gave her a more intense period because of the hormones in it? Or maybe she just happened to catch a cold bug and have period at the same time? Or if it is possible pregnancy/ morning sickness?. And I'm a little worried it could be something severe like an ulcer or uterus issues? Thanks in advance for any help, hope this is posted in the right place.

The plan B pill should really be only for emergencies and not be used as a regular birth control. Taking it a couple of times within a 2 month period is too much.
Hormonal changes can definitely impact the course of the period.
You should not have unprotected sex if you do not want to have a child right now.
Your girlfriend should talk to her doctor about taking the birth control pill and about her symptoms if she doesn't get better.
How old are you guys?