HELP NEEDED- CHEST PAIN!

Obviously I'm going to the dr for this as soon as they open...but I wanted to get everyone's opinion and see if this has ever happened to anyone. I have had this happen now 4 or 5 times in the past almost 8 months. It happened again last night. Right before I go to bed, my heart sounds "sticky" or in last nights case..sounded like it was vibrating. I laid on my left side and the sound went away. I woke up during the middle of the night and I have chest pain/heaviness right in the middle of my chest, only when I inhale. This pain will last for two days. I am 7 weeks+ pregnant. This is the second time this pregnancy this has happened. Anyone have any clue what the heck this could be?!?! It's painful and scary and I saw my dr about it and they did blood tests and and EKG and all were fine. I've actually had two EKGs this year for it. Any input is appreciated! Also note- I'm on progesterone suppositories.