6 weeks & 2 days

About a week ago I took some tests, and they were all positive. I wasn’t exactly trying for a baby but now that it’s happened I’m getting excited! I was wondering what other mommas did to stay fit and healthy and reduce chances of stretch marks during pregnancy? Also when did you make your first appointments? I hear that if I go in 7-8 weeks I would get an ultrasound the first time I go? I really want one, so I hope so! I also have a 5 year old and I’m trying to figure out how I should tell him. I want to tell him soon, but I am not having this baby with my sons dad (broke up a while ago) and I know his dad is going to be bitter about the situation so I feel like I need to wait a little while. If anyone has any advice that would be wonderful’ thank you :)