Should I go and buy a test now, or wait a couple more days..?

[Maggie J]

I was supposed to start my period the day before yesterday and I'm very regular and the day came and went and still today I've not started. I haven't shown any of my normal signs that I'm going to start either. Me and my b/f dont have protected sex (want a child) and we had sex around ovulation (if i did infact ovulate then) so it's a good chance. Only thing that I have noticed is for about the past week ive been having cramps off and on and they hurt and are unlike my period cramps. I'll have one and as soon as it comes, it goes away and then it'll happen again a little later. What are your thoughts??