I was just about to say that you really should get checked out. It can be a sign of pre-eclampsia (but not the only sign) or there may be other issues going on. It is a normal kind of thing in the last weeks of pregnancy but not second trimester.

It may be nothing at all, but it really is better to be safe, and if it is something at least you can work out how to manage it with your caregiver.

it turns out to be nothing! Let us know how you go!