I'm so scared to tell my parents I'm pregnant.

I'm 7 weeks and 5 days today. I'm pregnant with my 2nd child. I'm 22 years old. My son is 2 years old. My husband, son and I are currently living with my parents while my husband finishes his last semester of college (Graduating in December). Rent is just too expensive where we live and with school and me not working to take care of our son, that's pretty much why we live with my parents. I REALLY didn't want to conceive a baby under their roof. So this baby is a surprise just like my 1st. With my first, because he was a surprise, it wasn't a very happy moment when we told our families. They were really concerned about me not finishing college and being way too young. Anyways. It feels SO gross to me that they'll forever know we made a baby under their roof. And I feel like that's the biggest reason why I'm so scared to tell them. Well, that and I'm worried I'll get backlash like "you can't afford to live on your own so what makes you think you can afford another baby?!" The last few weeks I've been really lazy because I'm so tired and nauseous and I just haven't been able to keep up as much as I used to. They're noticing and keep calling me out on it everyday. Maybe it's because I'm pregnant but it's starting to make me cry. Like this morning my dad called me a mushroom because I didn't want to go to the park with my son as soon as we woke up. It's dumb now looking back at it but it made me cry. It just never ends. "Stop being so lazy. Play with your son. Why aren't the dishes getting done. Stop sitting around." Because of all the backlash I feel like I should tell them I'm pregnant so they'd back off a little on why I'm so tired. I just have no idea how to work up the courage to tell them. Or even how to tell them! Should I just sit them down and tell them awkwardly or is there a way to make it a fun announcement? I don't know. This was more of a rant and I just needed to get this off my chest. I just want this baby to be a happy thing.