How much water are you drinking? You HAVE to drink WATER! Might want to get a copy of the Egoscue book called PAIN FREE WOMEN. It takes you thru EVERY stage of pregnancy and the issues you have. I KNOW, thru personal experience - even though I don't have constipation issues, that when I do certain exercises, it makes me get up and go. Stop & think about it, when you move the hips, the bowels/intestines move with it. There are also HERBS that help w/ constipation that are safer than meds. Double check any precautions - alfalfa, aloe vera, ginger, lemon are all things that help stimulate the digestive system &/or bowels.
If you can handle lemon slices, try eating some of those, followed by plenty of water, of course since lemon eats at the enamel on your teeth. Lemon helps contract the bowels. I've used this NUMEROUS times w/ a small child and she loves lemon. It ALWAYS helps.
Make SURE you're getting PLENTY - at least 25-30G fiber daily. STAY away from refined sugar - slows down the digestive process and white flour.
You can do a "colon cleanse" by drinking a quart of distilled water w/ 2 teaspoons of sea salt. It's NOT really that salty, but trust me, you'll need to stay close to the bathroom for at least an hour to 90 minutes. Sea salt has great properties and REALLY helps clean out the bowels. This is actually part of the MASTER CLEANSE detox program. I do it 3-4 times a year, just to "clean that room of the house".
Realize that the biggest part of your immune system lies in your intestines. THEREFORE, if you can't get rid of the toxic waste, that's a HUGE problem. You're doing the right thing by trying to get some help. Just taking meds, stool softners, etc. is NOT the long term solution.
Get to know your body better and what things are required for your intestinal and digestive systems to function well.
Would be VERY surprised if utilizing even half these suggestions didn't make a huge difference.