Tight uncomfortable feeling after peeing?

So I drink a lot of water during the day usually 10 glasses. For a little while now I've been getting a very tight, slightly uncomfortable feeling across my lower abdomen as I empty my bladder and for like 20 seconds after. Especially if my bladder is more full. It doesn't hurt it's just new to me as a FTM and it happens very often but not every time.

Is anyone getting this feeling or anyone know what it is? It's not concerning to me just curious. And it's not a UTI I just had a urine test at a check-up. I'm 16 weeks. Thanks in advance!