Health & Medical >> Muscle and tendon pain

I have been working the heavy bag every other day for around 3 months. Punching and kicking. I have a pain in my left pectoral muscle that has been bugging me for over two weeks. I also get pain in the hamstring tendons by the knee. That is from when I kick too hard and too low on my heavy bag. Its like kicking a tree. But that pain goes away in three days and i can avoid it by lowering the bag to hit a softer spot. But the pain in my chest wont go away. Its just annoying and doesn't hurt that much but I think i keep re-injuring it. Do I need to give it a couple weeks? Go to the doctor? I started with 5-6 10 min rounds with 1 min of rest in between at 50-75% and now do 5-7 6 min rounds with 1 min and 100%.