Bestfriend vs Baby mama

My bestfriend is about to have a baby, with a girl he accident lying got pregnant.  I'm worried that when she gets further along in the pregnancy, and also has the baby, he won't have anytime for me. As selfish as that sounds we are very good friends. I understand a baby is a huge life changing thing, but I feel like it shouldn't drastically affect our friendship. Also when it come to the baby mama,  I don't know her,  idk if she's going to want to develop a relationship with him, if so she may not want me to be around him and their baby... How do I prepare myself? Or should I not be too worried?