I started having my period pretty regularly while exclusively breastfeeding when my daughter was 4 months old now she is 9 months I stopped breastfeeding a month ago, and have not had a period yet, it is about 3 weeks late. ( I have not had sex for 2 1/2 Months)

The best thing is to not get too worked up over it.
Stress will only make it worse.

My period was extremely irregular after I stopped breastfeeding. It's now back to normal and has been for awhile.
You body just needs time to adjust.

You could still be pregnant as some women have a period for the first few months..usually lighter but have it. Or it could be hormones. Make an appt with the doctor, or call OB's nurse.