Short answer
Serious concerns should be investigated honestly before Nikah rather than ignored because preparations have already begun.
Islamic Guidance
What Islam teaches
A person should not enter a marriage while deliberately ignoring material concerns or relying on false information.
Practical Guidance
What you can consider
Pause, verify the concern, consult trustworthy people and seek qualified Islamic or legal advice when necessary.
Sources
Qur'an 49:6; Qur'an 4:19.