Sparatic cramps (4wks)

I have had a previous MC (@7wks"but they didn't even see a sac....oviously I wasn't 7wks) so I'm admittedly a smidge batty :-) However my pregnancy tests are string and contnuing. I'm not feeling like I'm miacarrying. That's not my issue (I hope). But good lord woke up last night to the weirdest strongest cramps! And in 10 minutes they were gone. Has anyone had anything similar happen and have it be unrelated to