"I am at about cd 16 and I had some spotting when I wiped. What does this mean? Is it implantation spotting?"
At CD 16, it is highly unlikely that you are experiencing implantation spotting. More likely, the spotting could be a sign of ovulation. Especially if the spotting was accompanied by EWCM. EWCM with streaks of blood is about as fertile as you can get. So get yourself to the bedroom, ASAP (preferably, accompanied by someone with eager sperm).
(Yes, just when your DP thought descriptions of your cervical mucus couldn't be any more of an anti-aphrodisiac we go and add "streaking blood" to the description. As in "Come on, honey, I have egg white cervical mucus with streaks of blood! Let's get it ON!!!")
Of course, this talk of ovulation is all speculation without charting. Spotting could even simply be the result of your cervix getting bumped while DTD.
