Cramping at 30 weeks?

Erika ā€¢ šŸ’™5.12.15, expecting #2 šŸ’š 12.7.18
Hey ladies, I'm 30+2 and never done this before, so of course every little twinge is a new worry lol but the last couple days I've had some mild/moderate period like cramps in my lower belly. I've been having BH for a week or two and those have been stronger/more frequent the last few days. I had an ultrasound & baby was much lower than at my last visit & head down which I figure explains the pressure I feel down there, but should I be concerned about the cramping? I didn't see my ob but the nurse said try drinking more water but that hasn't really helped.