Late rent, when to evict? Oklahoma

[Sarah Brown]

Hello,

I am a fairly new landlord, with my second round of tenants.  My first tenants were amazing and I wish they could have stayed forever.  My new couple, however-have been full of excuses.  After much thought I gave a very young couple a chance, only because I thought it would be great to only have my house vacant for 3 days vs waiting longer and finding better renters.  Now it is 8 days into their first full month, and I have not received rent yet.  I have a high rent of $1350/month-$100 late fee on the 2nd and $50 each day thereafter. I made stricter penalties in the contract to hopefully avoid the situation I am in right now.  I sent them a default payment warning on 9/5, 5 days ago-and still have no response from them.  Should I go ahead and start the eviction process?  Does anyone know how long it usually takes to evict someone?  Any advice would be very helpful!

Thanks!