3wks pregnant and feeling something?

I believe I am 3 weeks pregnant, but I swear I can feel something moving!! Is it possible that maybe I got pregnant over a month ago and the test I took in June was a false negative? I also had a period in June but not July... Can you get AF If you conceive close to your AF start day? Because I took a test almost a week ago and it came out positive, so I assumed that I had conceived the first week of July but if I'm feeling it already (I think) and that can't be possible... I'm starting to think maybe I'm actually over a month pregnant and just didn't know it... Can anyone tell me what could be going on? Thanks!