Lower abdomen pain in pregnency.

I have my second pregnency at present , now thereis 19 weeks pregnency , and my level 11 is done and all tests are done , all arenormal but suddenly from previoudly week, i have started sharp pain in my lower back and lower abdomen , which i cant tolerate , rather it increases to mons pubis of vagina , so my dr prefers me normal scan on this , the ultradound was done and it was also normal , cervical length 3.5 cm and internal os is closed .. dr increases my medications ... suprox sr and susten sr ... now the pain is again started in morning ... aur drd kabhi bhi shuru ho jata hai... lekin scan maibhi kuch ni aya ... i want to know what is d reason behind that ki drd kyu hota hai ... my fst pregnancy is normal ... my bany is fine ... c section was done .. so plz suggest any home remedy or any medicine that i was get rid of that pain ... i was so scary about pre mature pregnency .. mam plz suggest me some remedies ...