Pregnancy after tubal ligation

I got my tubes clipped 3 years ago. For the last week or so I have been extremely nauseous, and going to the bathroom more often. My last "period" started the 19th of june and ended the 21st of june and it was pretty light. I'm scared I might be pregnant but feel like it's highly unlikely anyways. Anybody have experience with getting pregnant after a tubal ligation? I know the best thing to do is take a test but I'm waiting to see if I get a normal period this month and just want experiences until then.