1 wk late, light cramping on and off..

Will be testing tonight. I'm 1 wk late and I'm having nausea, dizziness, fatigue, and mild cramping off and on. My boobs aren't sore, but my nipples are slightly tender and a little darker than normal. I spotted for 4 days around the time my period was supposed to start (12/23 thru 12/26) and now there is nothing but water cm, and it feels like I've started my period at times but I go to the restroom and there is NOTHING there. I guess my question would be is it normal to have cramps come and go if I am pregnant?