Swimming I lakes or ponds.

Maleah • 21 year old Mama of a beautiful girl. She will be two in Dec 2018. Currently hoping on baby number 2!
So I got invited to go hang on a lake today and swim. I'm currently 14w5d pregant. My Drs office is not open on Saturdays so I'm not sure what to do. It's blazing hot outside so it'd be nice to get cooled off. Is this okay? I need some help.