Pelvic fullness and constipation, on birth control and had unprotected sex but he never ejaculates in me. could i be pregnant?

Probably Not: If you are using the birth control correctly and he has been withdrawing everytime, then you have been using two methods of birth control and it would be unlikely. However, note that the clear fluid that comes out of the penis during stimulation and before ejaculation ("pre-cum"), can contain sperm. In this case, your symptoms are more likely related to the constipation.