Questions on father's rights

What is the name of your state? Arkansas
Here is my situation**************my wife and I found out almost 3 months ago that I'm not our daughter's bio father. Our first doctor's appointment after the positive home pregnancy test, they did an ultrasound which showed her being 6 wks and 3 days. We did not know at that time you get credit for 2 wks before you even conceive. We found this out after the paternity test was done. All along we thought I was the bio father. Ever since the paternity test was done, in all consideration for our daughter, we agreed to let the bio father to start spending time with her 3 nights a week. (3-4 hours a night)
Our daughter is 1 week from her 1st birthday and bio father has not yet established paternity, through court that is.
My fear is that in the event my wife and I get a divorce someday, I won't be able to see our daughter. My wife says she agrees with me still being able to see her if that did happen someday.
Is there any way legally to have it on paper for me to have visitation in the event we do divorce? Or is there any possible way of keeping any parental rights other than adopting before bio father establishes paternity? Is there any way to adopt without mother's consent?