questions about cramping

how long does cramping last in early pregnancy. I'm pretty sure I ovulate around the 7th or 8th cause I started having symptoms right away. I've been having cramping for the past three days and some cramping last week. The app says I'm 4 weeks 5 days. Is there anything I can take for a pain reliever? I usually do heating pads for my menstural cycle cramps but I know heat isn't good during pregnancy? And they don't last all day it's every once in awhile through out the day!? I see doctor Thursday for blood work to confirm I'm pregnant.  Thanks in advance