I am in my 4th month of pregnancy. Currently going through lower back pain more on left side and some in the middle lower back from last 2 days. Lower back pain started around last week of 1st trimester which gets exaggerated when work involving back is there. Pain gets better in the morning after a good sleep. But gets exaggerated when lied down on bed even for sometime during day time. Standing up then gets difficult for atleast 1-2mins which gets better with movement. Still the pain is persisting. Can't go for any tests at this period. So just applying cream. And yes the pain increases when heating pad used, therefore stopped the same.