lauralaylin www.fertilityfriend.com is a free online charting service. There's an option to upgrade to pay for VIP, but you can get the same results through the free side.
Have you read
Taking Charge of Your Fertility? That's probably the best book that explains about cycles and fertility and temping and understanding how your body works.
Technically, implantation
can happen anywhere from 5dpo to 12 dpo, but it's most common to happen around 7-10 dpo. If you're 13dpo today, you can probably safely test tomorrow or Monday and know whether or not you're pg. Plus, if your temp continues to stay up, there's a better chance you're pg. You'll know AF is on the way if/when your temp drops very suddenly (like .5-1 degree from one day to the next)
Check out some of the charts in the gallery on
www.fertilityfriend.com. That can really help you get a good idea of what different charts (pregnancy, non pregnancy, etc...) look like.
I charted for over 18 months and it definitely gets easier to interpret the more cycles you have to go by. You'll also get a good feel for how your own body works and the signals it produces right around ovulation and again before AF. Good luck!
Hybrid Mode
