Anyone ever have "phantom kicks"?

Has anyone ever had them? Well I do and it scares the crap Outta me. I was a single mom when my son was born, about two months after he was born, I had a one night stand. (Don't judge) then after that, literally the next day my sons father and I talked and decided we needed to try to work things out. Later that day, the guy I slept with thinks he didn't pull out :/ I took plan b and went on with life. Two months later no period but was having these "kicks" like baby kicks. My oh my.... Things were going great with sons father and now I could be pregnant! I still to this day have these "kicks" but there's no baby. So anyone else have these? Or am I crazy?