I’m so worried ..

I’m someone who has bad anxiety in general and with this being my first pregnancy; every ache and pain I notice and obsess over. I’m 12 weeks today. Had an ultrasound last week and baby was perfectly healthy. Anyway, late last night around 2-3am I started experiencing sharp/intense pain up both sides of my belly and in my lower back. It comes and goes, lasting 5-10 minutes at a time. I took some gas x last night and some Tylenol thinking that may help. I eventually fell asleep but was woken up around 12 today with the same sharp pain, this time so intense it actually had me hunched over dry heaving. I have no bleeding or spotting and relatively no pelvic pain. Just up the sides of my belly and lower back as stated. I called my OBGYN and they got me in tomorrow for an US and chat with the dr, but I’m terrified. Anyone experience anything quite like this? Also, I have been having regular BM’s so it can’t be that either. Thanks :(