KL, I think we'd all be very unlucky to fall twice on the pill Weird enough the first time, think I'd scream should it happen again. Anyhow, my last Af was like that, I was sure I was UTD, face full of pimples, cramps, cranky and miserable... just took one night of good sleep to bring it on.
My AF has been irregular too - I'm still Bfing but she came back with a bite at 5-6 weeks

I'm sure everything will be okay, and if you are pregnant again you're a great mum and will find a way to make it work