Bp is 140/100 on medicine. Help. Reason?

My bp range is 125/90- 140/100 after medicine stamlo 5mg.I don't know the reason, I don't smoke/drink/perfect weight/vegetarian/very less junk food intake/ less sugar/salt intake/good sleep of 6-7hrs/ my job is peacefull. what other cause can b the reason ?not knowing the exact cause freaking me out more. I would really appreciate if any specialist can suggest/guide me. My Bp started 5yrs back during my twin pregnancy. Due to this I lost one of my baby(reverse diastolic flow) then BP continued. Pls suggest how can I reduce my bp. I've changed doctor but they all ask to do tests that i hv done almost all the tests periodically, which comes almost normal except last time my TMT while resting was lil fluctuated. Also can I plan 2nd child(pregnancy) at this range of Bp.