I feel your pain on not telling family members. I used to have a hard time telling my Dad because hes a Catholic, Id cook a huge steak dinner each time. But Id feel better afterward. Im also a total "daddys girl" lol so that may have helped. Anyway! Jumping off the soapbox, I agree that you should tell your family hun.
To release some of the mental pressure...tell ur family. Yes there's a chance they will be mad but we all make mistakes. Plus we don't live in the 50's.where its uncommon for unmarried ppl to have babies. Plus It's a new life. They may be excited for the baby. I was scared to tell my mom but I realized I needed to do it and I was stress free for the most part. good luck