15 weeks pregnant and Non Stop Cramping

I'm 15 weeks and 2 days pregnant this is my second pregnancy and since last night I've been having light to mild cramps they really don't go away. I'm constantly drinking water but I'm starting to get a little concerned that there not going away. Have any of you ladies experienced this as well? Oh and I have no spotting or bleeding I also tried called the nurse but they never answered I have an appointment on Monday any feedback will be very appreciated thank you :)