Gwen, I was told when I had it that the length of time that you are effectively covered for would vary slightly between each woman - for some it will wear off quicker and others will be covered for longer, that's why it is really important to get it every 12 wks, but I was like you and had zero libido when I had it so I had no intention of getting it a second time, but it was a good 6mths before I could say things were normal, so I have no idea if it still would have been effective or not, we used condoms as I wasn't keen on taking the BCP when things were so screwy.

If you think it is possible that you could be pg, do a test, it wont hurt to be sure.