Hi,
There's quite a list of things that can cause what you've described; just to name a few: fibroids, an infection, polyps, or hormonal imbalance, etc...Researching online is alright, but all the reading can sometimes be scary and overwhelming when it comes to trying to determine what the cause is. Your best bet is to wait for a diagnosis from the doctor. Meanwhile, get plenty of rest and try to take it easy for the next few weeks.
Take Care