Should i tell my parents im pregnant again or wait?

Well. Im 21 and just had my first child April 25 th <3. I am pregnant again and I live with my parents. I am only afraid to tell them because im afraid they will say it is still too soon after my daughter Peyton AND I DONT WANT TO HEAR ANY OF THAT! I dont want them to think i will be giving up on school or anything which i start on July 5th, but i will be taking things extra careful with my pregnancy. I have kept it from them for a week now and its bothering me not saying anything. By now i should be about 3 and 1 into gestation. When should be the best time to tell them??... after my first prenatal appointment (later this month, 29th) ?? or now? idk... help please