High Prolactin but no tumor

El
Hi Guys,
I had my MRI test done (with contrast) because of high prolactine (45.5) but the MRI came back normal. I don't understand  though why is the prolactin level high?! Is there anything I can do to lower it? My doctor thinks that high prolactin keeps me from getting pregnant. I don't know what to do.... I bought Vitex... I'm going to try that. What else should I do? 
Thanks!!!😊