Pregnancy cramps!....is it normal?

Brooke • Selena Jane Gonzalez - born 1/19/15 @11:56pm, 6lbs 13oz 💖 She is perfection <3
I just found out about 3 days ago that I am indeed pregnant!
Are cramp-like symptoms normal?
​I'm 3 weeks (according to calculations) and 1-2 weeks according to the Clear Blue Digital test (inwhich the instructions/directions sheet say I would be about 3wks from dr.'s calculations)
​My cramps have been coming and going for about 24 hours now. They're less severe than period cramps and they only last a couple of seconds. I read that women who get these cramps have bleeding or spotting, which I haven't. 
​However, from time to time the cramps are more uncomfortable than they are painful (kind of an annoying achey feeling). Anyway, they're not all that painful but they are worrying me. Is this normal?