Keep a close eye on your lower back pain. I was getting what I thought was lower back pain and ended up in emergency to have to get a cyst drained! Not trying to alarm you, but I was getting a physio to treat me for the back pain and it ended up getting worse until I ended up in ED.............
I don't have the constipation, I have the opposite! But I have plenty of leg cramps, which I think is a normal part of the pg journey........
I hope you start to feel better soon.