Getting Mad Exercise

Helo guys,.i want to go outside now for exercise hiking but im get mad. Its not easy if you have pregnanced. Im always feel sleepy and others. Oh my gush! Its not easy. That's why everytime that im plan to hike outside is destroyed. They said its needed or important to exercise the woman who pregnanced so that its not get hard for your deliver time. I hope next time im not get mad to do that exercise until my deliver time.