Worried about cramping

Rachel
I'm 6 weeks pregnant and I have been experiencing both sharp and dull pains/cramps for over a week now with the odd really awful cramps. The sharp pain tends to be on the right hand side and hasn't happened often but the dull cramps are quite frequent and feel a bit like a cross between that yukky feeling you get when AF is on her way and having a really upset tummy. I can't tell if the dull cramps are actually because (sorry) my bowel movements are all over the place or because my uterus is stretching or something else. Should I be worried that they have lasted over a week? This is my first pregnancy and I'm super paranoid about everything! I don't have my first midwife appointment until the 6th Sept but don't want to be "that" 1st time mom who calls about every twinge! 
I've not had any bleeding at all, not even implantation spotting.
Any help is appreciated :)