I think it is very, very unlikely that you could get pregnant right now. I wouldn't take Plan B, you are not supposed to have estrogen when breastfeeding (it can impact your supply), or at least not in the first several months.
This has great advice and can give you more information on what rules need to be followed to delay ovulation:
I see all the time on this site that 'women are very fertile after giving birth', well, that it only true if the woman ovulates. If she is exclusively breastfeeding, it is very, very unlikely that she will ovulate.
I was not brave enough to use LAM as our method of avoiding pregnancy, we used condoms, withdrawal and the mini-pill (for a while, it had too many side effects so I stopped). I didn't have a period until 9 months after my first was born and 23 months after my second.