Starting the 7 day break early?

[ViewFromTheAfternoon]

Forgive me for being thick I just don't understand.

I went on holiday earlier this month, I would've come on my period the day that we flew out but I didn't want to take two packs back to back so I just stopped taking the pill three days early. My periods only last 3 or 4 days which is why I only shortened it by this amount.

So what happened was, I took 18 pills (I am on microgynon btw) then stopped, had my bleed after 3 days then started taking the pill again after the 7 days were up.

Me and my partner are going to start trying for a baby in the new year so if I did mess up here it's fine, we aren't really going to be bothered. But from everything I have read it says I wouldn't have been protected but HOW? I started my bleed, so there's no way I ovulated because I was bleeding and as far as I know, you can't release an egg while you're on your withdrawal bleed. And then I started the next pill pack straight away so I would've been covered again. I assumed that the reason you have to take 21 pills is so that you bleed every 4 weeks like you would with a normal period. As long as my break was only 7 days it shouldn't matter?

Could someone explain to me why I'm wrong because I have tried to Google and can't really find the answer! Where exactly in this space could I have ovulated? It doesn't add up for me

I believe it's because you need 21 days worth of pills to build up enough hormone to protect you also across your 7 day pill free break. So by stopping pills before 21 days you haven't had the full amount of hormone, plus a 7 day break, which could have triggered ovaries into action.

In terms of yes having the withdrawal bleed as normal and potentially have ovulated with a viable egg I don't know the specifics of how that would work. But technically by what you have done you weren't fully protected, which is what google/pill packets will tell you.

But 21 days is the 'full dose' of hormones to protect you for 7 days without the pill. Same theory if you have 21 days, then longer than 7 days without taking it again, the ovaries can kick into action.