Why my whole chicken has strong odours and smells so bad,but the smell of it isn't sour and its 2 days before the useby date,isit safeto eat?

You have a nose for a reason. Chicken is not supposed to stink. If it does throw it out.

that date means NOTHING if the meat wasn't handled properly. THATS why experienced cooks/chefs do NOT base all decisions on that arbitrary date alone.
If your chicken stinks, its spoiled. toss it. it doesn't matter what date is on the stinky thing.

No, if chicken smells bad, it IS bad and you need to throw it away. When you buy chicken and bring it home, it needs to be used within a couple of days no matter what the sell by date is.

When in doubt, throw it out. It doesn't sound good and if it is bad it can make you very ill.

Chicken is the one meat, above all others, that I would toss just for those reasons. If you have doubts about poultry, toss it.

It is bad.