Has my breast milk been contaminated?

B

So i have just recently started using my Haakaa to pump some milk and try to start introducing a bottle. It's not going well so far, my little one just doesn't want to take it. He's 2 month old and has been ebf. Anyway was trying to express today while feeding and my 4 year old is running about crazy, baby is fussing and I'm struggling with the Haakaa - safe to say I'm stressed. Once id finished I popped my Haakaa on the table beside me and turned away for a sec to get the lid and there's my 4 year old with his face right up to the opening of the pump. I was so upset, have no idea if maybe some saliva fell in or not or maybe I'm just overreacting due to being a bit stressed Should I chuck it? Or am I being irrational? Also if anyone has any tips on how to introduce a bottle that would be greatly appreciated!