My A/C blows out hot air every couple days

The only problem I could think of is that the air conditioning needs to be recharged as they call it because over time it will run out. You can usually go to a place like Firestone and they will do it (depending on how much you need) for around 100 or you can find a way to do it yourself you would buy either R134A or Freeze 12 that might be harder to get but cheaper

It's freezing up. The evaporator is probably dirty and when it is used for a couple of days, it freezes up and the warm air you are trying to cool as woking its waya round the blocked fins and not exchanging heat for cold.
When you shut it off, the ice blockage melts and you re-start and it works fine until ice forms again. Get it cleaned!

(The House A/C unit evaporator, not the car at firestone?????)