Working out while pregnant

So before I got pregnant I was working out 5 days a week. I stopped when I found out I was pregnant for personal reasons, but now that I’m 18 weeks I wanna start working out again... does anyone know if I’m allowed too?? I didn’t know if the break in between was gonna matter.. also I should include my body is use to picking up and sometimes holding my 45 pound child and so far this pregnancy has been without complications. The exercise I would be doing is just the exercise bike a few times a week.