How far along are you? If they continue then you should go to your doctor, definitely.

If you're due soon then it could well be labour starting!

I'm 36 weeks... I'm not due until the 28th

Well, you're practically full term so it might be labour or just painful braxton hicks. Does the pain come in regular waves or is it continuous? If it continues or gets worse then go see your doctor or midwife asap. I always err on the side of caution!

I've been having them on and off for over a month.
For the last two days they've gotten worse and more often.
I'm 3 days past my due date.
My doctor said it means i'm effacing.

What's effacing? I'm having them all day. They started last night and they are continuing throughout the day. I get them and they last a minute or two and then I don't get tham again for a half an hour or so... At first I thought it was just pain from her being engaged already, but they are getting pretty intense... They happen at least twice an hour.

Effacing is when your cervix thins out.
That's more than likely what's happening since you're only about 4 weeks ago. That's when mines started and i'm 3 days over.