Implantation bleeding and spotting happen about a week after ovulation and fertilization. Implantation is the attachement of the fertilzed egg, the blastocyst into the lining of the uterus. Implantation happens about a week after ovulation with a range of 6-12 days. Some women report some spotting or bleeding around the time of implantation.
Most women report this bleeding to be brown in color though some mention it to be more reddish. Most women report at most a few drops of blood — maybe one to two small red or brown spots in the panties, though others report a more substantial amount but rarely if ever does it approach the appearance of mentrual bleeding.
If your bleeding is similar to a menstrual period chances are that it's not implantation bleeding.
It's likely that most women who do become pregnant do not experience implantation bleeding, and many women experience some spotting but they are not pregnant.
If you experience bleeding regularly after ovulation and you are not pregnant then you may want to discuss withyour doctor whether some tests can be done to make sure everything is OK.