Maternity Leave

I'm about to start a new job, but they do not offer maternity leave. My fiancé and I are getting married in 2 weeks, we are both 34yrs old, and would like to have at least 2 kids. I train horses and teach kids how to ride horses. This new job is a great opportunity, but I kind of feel like I have to choose between job or kids. How long would my body need to recover after delivery before I could be physically active again?