Negative pregnancy tests but missed period

I need some advice....I'm 31 and my husband and I have been TTC for baby #1 since March. I was on birth control for 12 years. Since going off birth control I have been very regular. I would get my period between cycle day 25 and 29. It is now my cycle day 32. I have taken three pregnancy tests and all of them have been negative. Should I call my OBs office and see what they say or do I just keep waiting for my period? How long do I wait? I just want to know if I'm pregnant or if something is wrong. Thanks!