Jaimee, for what it's worth, I could see myself getting pregnant in either of those situations, maybe less likely 2 since I would assume that I have no clue what is going on postpartum, so I would be careful just in case (coupled with my strong desire to not conceive a baby and then have a short LP), I probably would have avoided #2, but #1 was a method failure for the Last Dry Day Rule and the Doering Rule (my personal favorite). Sure, it wasn't a failure for the 20 day rule or the Clinical Experience Rules (both having last day of Phase I on CD 6), but you're definitely a statistical outlier.
Also, before I seem to critical of the mucus only methods, I do know that Creighton at least has a much more systematic way of looking for and at CM that yields a higher effectiveness rate. The Ovulation Method (Billings) has been tested to be about 96.6% effective (perfect use), and Creighton claims a 99% effectiveness, but people using the STM seem to have a higher failure rate (3-7%) using the Last Dry Day Rule even though it is theoretically the same thing. I certainly don't want to claim that you were not making your observations correctly, but it's hard to tell if the techniques used in Creighton could have given just that little bit more effectiveness.
On the STM side of things, some people recommend making internal mucus and/or cervix observations as well, and some couples find this to be helpful in finding signs that their bodies are approaching fertility in cases where their external CM doesn't give them enough warning.