How late after a missed period should i worry, i am trying to conceive. usually my cycle is 21 days and i'm currently on day 31, with all negative t?

Not sure.: With 21 day cycles, they are a little on the short side, and you may not be ovulating on a regular basis. Consider using an ovulation detection kit and if it shows that you are not ovulating, give your gyn a call and discuss this with them. If so, you may benefit from some low dose oral fertility medications. Hope this helps. Good luck.

??: Cycle length is first day to first day. 21 days is extremely short, if add cycle of say 5-6 days that is a 26 to 27 day interval? If you are at 32 days and negative test, would seek out a serum quantitative pregnancy test and if recurrent, would have an evaluation to look at ovulation. If cycles are often less than 27 days in length i would strongly consider diminished reserve and endometriosis.