body preparing?

Last week I had the runs all week off and on. Strong hip aches, back aches & some tired spells where all I wanted was sleep but didn't ever nap. This week I have had a bunch of energy. Tried finding things to do& have had strong lightening crotch, pelvic gridle pain & some huge cramps plus some vomitting & sickness! 
Is this body preparing for baby? Anyone else experience similar?