Thanks for using the forum.
That is a lot of urination. If you are concerned, or experiencing any other symptoms such as pain or burning on urination, abdominal, side, or back pain, or notice a change in color or a cloudiness of your urine I would call your doctor. These can all be signs of a urinary infection and should be followed up on immediately. It is possible that you are drinking more fluids that normal and being stuck on bedrest, getting up to urinate more frequently. Additionally, pregnant women often have an increase in frequency of urination. This can be due to hormone and physical changes of pregnancy.
Congratulations on your pregnancy. I hope this helps.