Someone please give me advice .

I'm 19 days late on my period , I've been peeing a lot more then normal. A couple months ago I had cysts but my period was on time . It's only been late one other time . And that was bc of the cysts . It's never been this late before though. I haven't taken a pregnancy test yet . I took one right before I was late and it said negative . I had some nausea and cramps but they're gone now . They seem to come and go. Could I be pregnant or is it just the cysts ? I really need some advice