Dogs Tested For Parvo

Long story short, my bf got two 8&11 week old dogs from two separate litters 5 days ago. One was sick when he got her, I told him but he didn’t want to listen. Days later she declined DRASTICALLY and ended up in the hospital. She’s doing better. Well 2 days after that we had the the other dog tested and he was negative. Earlier today my dog threw up(clear liquid) which is not abnormal for him to do from time to time but later tonight he threw up his food, which he has never done. But he has been having issues with his stomach, we took him to the vet last week. So we automatically took him to the VET ER just to be sure because that is one of the symptoms. He also tested negative. So their both negative.

Should I still be worried? I am a mess. So scared for my baby