It is very common with Christians to believe they have heard from God concerning someone being their mate. Sometimes they are right, sometimes they are wrong.
What if you are wrong? Don't feel bad. Happens to plenty of Christians. It may have been your emotions, may have been a genuine demonic deception or just spiritual immaturity. If you have been wrong, spend time with the Lord and ask His Holy Spirit to heal you. Then move on!
What if you are right? Doesn't mean it will automatically work out. I have seen this plenty of times. The problem is, you AND the other person have to agree with the Holy Spirit that you are called to marry each other. Because God gave us free will, the other person may refuse to agree. Why? Usually they have someone else in mind. Or they have unhealed hurts that they have not allowed God to heal.
Let's say you are a 35 year old female who wants children and doesn't have any. You have had a "word" about someone for two years but that person either has no interest or hasn't married you. Would it be wisdom to wait another three years? Not if you want children. Cut your ties, and believe God to send you a Christian man who wants children and will commit.
What if you are older man and you believe you have a "word" for a woman, but she has told you she is not interested (more than once). You hang on for a couple of years believing God to change her heart, but she still is not interested. I suggest you move on. Why should you waste any more time on someone who isn't interested? God does not hold you responsible for someone else's disobedience.
If you read Where's My Mate? The Lord spoke to me about Lucas 11 months before he proposed, and we were married 3 months after that. It wasn't easy, there was spiritual warfare, and unsolicited advice from friends/family we had to overcome/ignore, but ultimately we fell in love with one another and moved forward.
When the Lord spoke to me about Lucas, I prayed the following scripture asking God to confirm His word in the mouth of two or three witnesses. He answered the prayer! (testimony about this in Where's My Mate?)
This will be the third time I am coming to you.
I suggest you pray asking God to confirm His word about the person you believe you are to marry through the mouth of two or three witnesses!