When to stop BC pills??

Haley • I am married to the man of my dreams and we have two beautiful little girls (8 and 2) and another baby girl due in May!

So we very suddenly (in the last week) have decided to start trying for our third baby. I'm almost halfway through my pack of birth control pills and I'm not sure if I should keep taking them to finish the month or just completely stop now since we'd like to start trying immediately? Any info/opinions/comments would be great!