I Have A Low Lying Placenta Im Over 22 Weeks

I have a low lying placenta im over 22 weeks pregnant and my stomach hurts everyday all day i told my doctor but he doesnt know what it could be. I want a second opinion on if i should be resting and not working right now i feel pressure on my vagina area and i dont lift anything cause it makes the pain worse. I did bleed and spot the first 2 months when i was working but when i stopped working it quit but still have the stomach pains. My mother is worried so am i ive never felt this before with my other kids.