Moderate Cramps

This is my first pregnancy. I am about 4 weeks and have a doctor's appt next week. I have been having a lot of cramps with no bleeding. My lower back has also been hurting pretty bad. I thought I was having very bad PMS but because my nipples hurt sooooo bad and I was a day late I decided to take a pregnancy test and woaaala it's positive. Is this normal? The cramping and back ache are constantly there and intermittently my cramps get bad. Any advice? Can I take anything for the pain? I haven't been sleeping this week either , another sign that something was going on. Any advice would be much appreciated. 😊