death to capslock

Because I was re-reading some old recaps in various places, and it suddenly struck me that there's an awful lot of speculation that if someone screwed up/deliberately skipped the contraceptive potion, that someone must have been Tonks. I've wondered about that possibility myself. It seems primarily based on two factors: (1) Tonks was pursuing Remus in the previous book, and he was reluctant for various and possibly-not-all-stated reasons, and (2) that's how the most reliable Muggle contraceptive method works.

Tonks was indeed pursuing Remus. She pressured him by debating the merits of their relationship in public, thus bringing more peer pressure to bear on his decision. But do we know her well enough to know whether she'd force a baby to participate in this drama? Hard to say, really - I'd be open to arguments either way. And since for the most part she only discusses her relationship issues in private with a very few people as far as we know during that whole year - granted Harry isn't around enough to provide reliable observation on that point, but at least she doesn't ever start telling the kids her woes - it's possible that the scene in the hospital wing was a stress-induced lapse on her part, if you want a more charitable reading.

So point 1 could go either way, and as for point 2, we can't rely on magical contraception being a perfect analogue of ours. Why couldn't they have a Spermus Mortalitus potion? (Or an easily-reversable Vasectomus or Fallopius Tie-us spell, for that matter... And yes these are all bad Latin, but so is JKR's.)

Just because Tonks ended up being happy about the results doesn't mean it was her actions that led to them.

And in canon, who is the person we know to have forgotten to take a very important potion at least once before, consequently endangering others and causing himself trouble as well?