Tummy pain while peeing?! Please help me out

Promise • 23. First time mommy! June 28th due date!
I'm 28 weeks on Monday, I just went to pee and bladder was quite full and as I peed my stomach tightened up so hard and hurt SOOOO bad (I screamed a little) I've had this feeling before while peeing but it was bearable; this time was just the worst with the most pain! It only lasted a moment after I was done peeing. Please tell me this is normal? No more pain afterwards.
Doctors appointment not until the 13th of April.