Nausea and stomache pains

Hi, I'm 15 and this month me and my bf had, well yanno,(I know it wasn't the best age, don't judge me please) anyway, it was around the 5/6th of January (I had already had my period pretty much the end of December, but I've been okay since last Friday night, I felt really sick, I thought I was just ill or something but from now to then I've been waking up feeling sick, with a painful stomache sometimes, I feel like I'm going to be sick but I don't actually throw up, I feel bloated, the bottom of my stomache hurts most the time since Friday night, my period should come around the end of this month, but this has been really weird for me so I was wondering if anyone could tell me if they know what this might mean, please help?