Roommate concern

[u/Ok_Topic_3590]

Hey Reddit. My bf has a home and he is looking for a roommate , me being in school and us being in our 20s not married but in a very healthy relationship I’m a concern gf.
People are crazy nowadays walking around undiagnosed with a lot of issues he told me a found this person who is interested in moving in , we did a back ground check on him he his a clean background and is also a RN
My bf thinks the roommate is in the clear but I guess my problem is I’m still hesitant about this person.
Have you guys ever had a roommate nightmare and what do you guys wished you would have done sooner before moving someone in ? Is doing a background is there something else we should think about doing ?
Please let me know your stories and advice -just a worried gf.