C.O.
wait...didn't you say in one of your earlier posts you NEVER get your period?
When is it considered late? Well, if you have a normal cycle and it is after your normal expected date of starting..then you are late. however, if you do not have a normal cycle? It's hard to say.
If you feel like you need to test for pregnancy? then do. Go to the dollar store and buy some pregnancy tests and keep them around.