Chemical pregnancy

Vicki • 33 years old ttc #1 been trying 2.5 years....
Hi just wondering if anyone has had one? I was 6 days late with no period symptoms at all then day 7 my period arrived out of the blue and I've never felt pain like it and I was so heavy! It was only for one day and really red, nothing the day after and then really brown bitty discharge.The nurse suspects that's what it is but I wondered if anyone has had similar?? Thanks xx