How do you know difference between normal and something wrong

The last few days my three week old does not want to lay on her back at all she’ll start to moan and groan and then start to cry like she’s in pain and then only wants to lay in our chest and then sometimes she even picks up her head starts to cry like she’s in pain and then go back to sleep I’m trying gas drops and gripe water I just don’t know what else to do she seems to be so uncomfortable.