Cramps - 5 months along

I'm just about 20 weeks and started having some side pain on the right side. I have gone to the bathroom and made sure I'm not constipated and also been drinking water. It kinda turned into dull cramps. Strong enough I know they are there .about where my baby lies. I don't want to rush up to er but also a lil scared :/ it's been like this for about an hour