Hey hun!
Well first off Congrats on your pregnancy!! And its going to be alot easier with your mother supporting you in the situation!! I would definitly sit down with your dad and lay it out straight!! Sugar coating it will not help!! Trust me, Im 31weeks pregnant and the sugar didnt help lol;)
Anyways just let him know your views on it and what you plan on doing!! For instance staying in school, working to help with the child, etc..
Stand up for yourself and be strong!! Everything will work out hun:)