Why? In only a number of hours?!!

Now I'm getting nervous. It's 9:00pm on Sunday night my 17dpo. I emailed my doc tonight to say I was going for bloodwork in the morning for hcg and p4. I made it this far.... My nipples are so sore they feel like they are going to fall off... but this morning's temp was only 98.1... down from yesterday... and now... I think I might be getting cramps... slight menstrual like cramping... why???? Why??? Please why? I hope and pray that its just gas... or at least to have the grace to deal with it if its not. I'm so close. Hang in there baby. Hang in there little babie.