I get mine checked once a year with my annual check ups to make sure all is well. My previous doctor felt we just needed to check it with the annual check up unless I felt something was off. Had to get a new doctor last year after moving across the state. My new doctor also felt since I've not had any issues that checking it once a year should be fine just to make sure it's alright. My old doctor even covered the cost of it when my husband was unemployed and we didn't have any insurance as she felt it was that important and knew it was going to be a strain for me to pay for it.