Should I call my doctor? please comment

So a little backstory I had severe nausea in my first trimester and it got so bad that I had to go to the hospital. The nausea stopped completely at 14 weeks. One week ago ( 19 weeks) I had dark brown discharge and I went to the hospital and they said everything looks good. I followed up with my doctor and she put me on bedrest but told me everything looked good. So I'm 20 weeks right now almost 21 and for the past two days I have had really bad nausea and I had a sharp pain in my stomach about 5 times every day for the past couple days. Should I be worried? I can't figure out why this is happening and I'm wondering if I should call my doctor. What do you think?