Ttc!!!

Okay guys its been 3years no baby but im excited but skeptical to say that last month i had a period. This month May 10 i thought it was a period so i put in a tampon and went swimming . The very next day no period or anything. Ive been having slight cramping and feel as though im going to get my cycle back but when i wipe its NOTHING. I took a pregnancy test but it came out negative due to inaccurate results because it wasnt in a sterile cup. So tomorrow ill take one again . Has anyone ever experienced a period for one day? Im not on bc or anything.