Why is it blurry when i put contacts on?

Dirty vs wrong ones: If your vision doesn't clear up after putting on your contacts, perhaps they're dirty & need to be cleaned or replaced. Or if visual acuity is different for each eye, perhaps you reversed your lenses. If none of the above, go see your optometrist/ophthalmologist for an examination to see (no pun intended) if your visual acuity has changed (worsened).

Many reasons: Probably the contact don't fit well. You should not wear them if they are not comfortable.