It's normal to have lots of lows at that stage of pregnancy. I had to eat sweets and keep Lucozade beside me at night.
As the PP said, soon you'll become more insulin resistant and your insulin needs will rise. If you have Think Like A Pancreas or can get a look at it, there's a useful little chart which gives you an idea how your insulin needs will change during pregnancy.
I was told to keep my spike below 8 after meals, and my before meal sugars in the 4s or 5s. Obviously, that's not always easy, especially when your needs are changing, but I tested frequently and corrected if necessary
Speak to your clinic. Mine has a special DSN for pregnancy. I was really well looked after by my team and they were always available to help. Don't be afraid to ask as that's what they're there for .
Good luck. X