I am sorry to hear what happened to you. If you told him that you did not want sex with him and he still did it, it is rape.
As long as you have been taking your pills as you should, the chance is extremely small that you will be pregnant. It may be worth your while to get tested for an STD. If he did this to you, he probably engaged in unsafe sex with other girls.
My suggestion is that you do tell your mom. You need some support from an adult that cares for you.
Best of luck!