I don't no if it's because I'm nervous ?

I have read so many different answers to this question on lots of different sites! I had unprotected sex with my bf about 10 days after the first day of my last period! He did cum inside me and now I'm experiencing some weird feelings! It's now been 4 days and I have got a bit of back ache every now and again, but consistent stomach cramp all day everyday! I feel myself getting a bit emotional over stupid things and also being moody! I don't usually experience cramps at all until the day before I am due on but this is a couple of weeks off yet? I don't no if it's because I'm nervous that thinking about it too much but the stomach cramps are definetely there all day! And my toilet habits are the same? If I am pregnant I will be happy as we're not trying as such but if it happens it happens! Hate having to wait to find out! Can someone shed some light on this!