I had ms from about 7 wks to 15 wks, and then it came back about 26 wks. I did notice towards the end of my pregnancy I'd have off days, and usually got sick due to bad hb, especially at night (it got really bad at 36 weeks). I do have to say though about 34 weeks, I started to feel off, not sick or anything but off. It got worse at about 36 weeks, and progressed up until I had DS2 at 39w1d.