Irregular period?

Hi I need some advice, I came off the pill about 7 months ago. I've has a period every month arriving from cycle day 23-25 which has always been normal for me, even before children and birth control..

Strange thing is last month I had spotting mid cycle and then I started my period on cycle day 19 which lasted for 6 days quite heavy. Fast forward to this month I'm now on day 29 and no period... negative pregnancy test.

Has this happened to anyone before and what was the outcome? Should I go and see my doctor?