@Hollie85 Please don't beat yourself up. You didn't do anything wrong. I have been in your position and felt (still feel on occasion) that I could and should have noticed things sooner and done more. Sometimes, you are not the one holding the cards. Sometimes, the decision is taken out of your hands.
I'm almost 6 months post-loss, and still get pangs of guilt and sadness. But I know, deep down, that I did what I could. Your little piggy would not want you beating yourself up or blaming yourself. Piggies are masters of disguise and will be ok even when they're not. Your little man would love to be able to tell you it's ok, it wasn't your fault.
Contact the Blue Cross, have a chat with them. It's hard to come to terms with an unexpected loss. It will take time, but you will get there xx