I strongly recommend that if there is even a tiny doubt in your mind about a non-family adoption that you back away from making a committment to the couple that you met. There is no need to rush into making a decision.
I am the grandmother of a 3-yo boy. My daughter was single and very uncertain about being a mother. She was being pushed very hard into making a committment to a couple to adopt her child. We decided to wait until after her son was born to get involved with adoption. We felt that it was unfair to our grandson to not have time with his mother (even it was a few days) and unfair to the hopeful couple whose hearts might be broken. In the end, she did bond very strongly with her son and is raising him. We had no way of knowing before the birth.
We found some information in pamplet that helped us a lot as a family -
http://www.cubirthparents.org/booklet.pdf
After we read it, we decided to slow down the adoption plan and wait until after my grandson's birth to decide.
Good luck, breathe deeply, and tell everyone to back off and give you space to decide.
Happy G'Ma