Yay Deb!! This is wonderful news.
I had implantation with my first pregnancy, and it was a day or two later then AF was due. On and off again for a couple of days - very confusing! Specially since I was in Vietnam and was trying to decide whether to drink, whether to use a tampon, and whether to eat those interesting vietnamese delicacies! Happily I did all three, and it petered out after about 2 days, and the sickness swept in.
Wonderful news, I'm sure the HCG monitoring will be a blessing for you, and this pregnancy will all go to plan.
Fi