Help!

So I’ve been experiencing some cramps in my lower right abdomen. They’re not like period cramps and I never experience cramps before my period or during ovulation. I’ve noticed some other things that aren’t really normal but I just don’t know what to think. My periods are irregular and I’ve been terrible at keeping track of when I last started last month. It’s been a month to almost a month since my last period. I went and got just a little cheap pregnancy test but it came out negative. I was told to wait a couple days and test again. What’s the best kind of pregnancy test to get? Ntnp