Ask your gyno. It's usually happens. As baby grows, it will take space inside and tummy will be like tight and hard feeling. Don't press tummy area. left side will be our stomach and right side baby. Don't worry it's normal. Still if you have any doubts you can consult your doctor. When I was pregnant I liked to keep a hand on it and feel my baby. Such an awesome feeling.

As you are towards end of pregnancy, you might feel this due to growing belly. Try to keep a pillow near ur belly when you lie down. If you still feel unbearable tightening pls consult doctor

if it's increasing please consult doctor