I would definitely listen to your body at this point.
When my wife was pregnant with Connor she just wasn't able to workout at all, prior to this she was an exercise fiend 5-7 days a week...etc. During the pregnancy she was miserable. The first trimester was the morning sickness that lasted all day and the 2nd and 3rd trimester was intense pains in her back that the doctors couldn't figure out. At this point we definitely were not stressing that she wasn't working out like she used to.
"And for crying out loud. Don't go into the pain cave. I can't stress this enough. Your Totem Animal won't be in there to help you. You'll be on your own. The Pain Cave is for cowards.
Pain is your companion, don't go hide from it."