What side effects can you have if u take clomid (clomiphene) 50 mg, just 2 pills and then stop abruptly ?

No effect: It is not likely that taking Clomid (clomiphene) for two days would do anything to you. 2 doses is not long enough to trigger ovulation. Stopping it is not dangerous. It theoretically could interfere with your cycle by causing some bleeding but not likely. you can just wait a few days and see if bleeding occurs. If it does it should resolve on its own quickly.