Cramps but no period

My cycles are usually 28-30 days long... This cycle, on CDs 24 and 25, I had lots of cramping and was sure AF was on her way... No period. Had cramps again on CDs 30-32, with still no period. On CD 33 today, with no cramps and no period. Scared to take a test ... I know that's so silly ... But last month AF came 15 mins after I took the test.