Lake day?

When I was pregnant with my son at 4-5weeks I went swimming in the river, I didn’t get an infection and baby was fine. It was my first pregnancy everyone told me it was fine. With my daughter I steered clear just because we were prone to losing her and I didn’t want to cause added stress, and then 5 months after my daughter was born I miscarried at 3months pregnant. So now that I’m pregnant again 6months after my miscarriage I’m scared to do anything, I am 3-4weeks with this pregnancy. We were invited to a Lake day I was wondering would it be okay to go in the lake? I have to take my two children in so I’m wondering will I be okay? Or should I see if someone else can take them in?