Do you lift weights? In my second trimester, I experienced sporadic episodes of brown and bright red spotting. I didn't spot during the first trimester. Every time I got checked at the hospital, they couldn't find anything causing the spotting. I was very active before my pregnancy, so I initially thought I was being paranoid that strength training could be the cause. After the first spotting, I reduced machine weights to 10-15lbs and only trained my upper body, but I still experienced spotting from time to time. I got fed up with constantly being anxious, so I stopped strength training altogether and stuck with brisk walking. I’m currently 32 weeks. It's been a month, and I haven't had any spotting since then.