Drinking milk in my tea it’s use by date was 6 days ago but looks and tastes fine will I be ill ?
If milk passes the smell test then it's probably fine.
Of course not. A date is only a date, and it's there to protect the store, not you. Use your senses. If it still tastes OK, it IS OK. Most often the date on milk is a week or more before the time when it starts to taste nasty if you keep it cold, so I ignore it and rely on my taste buds. How else did we manage in the days before there were dates on food? We looked at it, smelt it, tasted it, that's how.
You will find out.
why would you be ill if its not spoiled? Milk does not spoil in a way that you wouldn't notice. In any case spoiled food rarely makes anyone sick and only makes the milk nasty. You are fine.
If it looks and tastes fine it will be fine.
In your milk were probably added some preservatives (E200 - E299) which maked it more persistent.
I've accidentally drank a whole glass of spoilt milk without realizing it until the aftertaste hit me (my nose was stopped up so I couldn't smell it), and I was just fine. As long as it doesn't smell bad and isn't curdled it should be fine. Even if it is bad, spoilt milk doesn't hurt too much to drink, and even if it did, you diluted your milk with tea so it isn't as harmful.