4 days positive opk?? Is it possible?

Ive gotten 4 days in a row of positive opks. I'm testing in the morning (I drink a ton of water during the day and afraid it would be too diluted in the afternoon/evening). I did do one test last night that looked like the line was fading, but this morning looks clearly positive again. 
​I'm also getting cramping/pulling off and on on my right side. Sometimes it's worse than others. Not excruciating, but enough to make me stop and take note. 
​Any thoughts on this??