Any advice?

Today I found out I'm 6 weeks pregnant with twins. I'm so excited but nervous at the same time. I have yet to tell my parents and I know once I tell them, they will be disappointed. Back in March we learned that I was pregnant & our relationship went downhill. Once I lost the baby back in May, I felt like they were somewhat relieved. My mom even hates when I talk about my previous pregnancy.... I'm only 20 and in my third year of college, so I know it won't be easy for them to take, especially a second time around. I'm waiting until my birthday to tell them the news, which is in a week and a half. Sooner the better, or should I wait?