Wondering how many pregnant women spotted?

Hi. My husband and I have been ttc for about 2 years, with no luck. My periods are always very, very abnormal. Well I am taking Glucophage (since October 1st) and when my husband gives a 50% mobility sperm analysis I will be put on Clomid (his last test was 49% and they wouldn't give it to me.. Ugh)

Well I read that sometimes Glucophage will help women ovulate, and can often get pregnant without even taking Clomid.

Ok now my question, I have never ever in my life spotted between periods but last week I spotted for about 3 days. It was a really really light pink/brown color, and was not enough to wear a pad or tampon or anything, just a light panty liner to keep from ruining my underwear.. Is this typically what implantation bleeding looks like?

I know the only real way to tell is to take a home pregnancy test, but before I go out and get excited and get that damn negative sign once again, I just thought I would ask how common is implantation bleeding, and is this what it is like?

Thank you so much!