pelvic pressure.... when to worry?

I have been having more and more pelvic pressure the last couple of days. Very mild cramping. Mostly just the pressure. No spotting. Do I need to worry? I was just in the hospital a week ago and they thought I had a funneling cervix but it turned out to be fine and not opening. My cervix was at 3.7mm. Could it change in a weeks time? Shorten so much that I am feeling pressure? Any advice is welcome. Thanks ladies. I really don't want to run off to the ER unless really necessary.