Having triplets. How late will they let me go?

A long as possible. Generally with multiple births pre-term labor is a real possibility so your peri-natologist will monitor your babies and check your cervix for early dilation. You will be allowed to 'carry' the babies as long as possible as long as your health is good (e.g. No pre-eclampsia etc..) and the babies are growing normally (on ultrasounds). Congrats on the 'three-some'!