How do I get way more Twitter Followers?

Hi guys,



I have a tutoring biz and I'm present on social media: Facebook, Google+, and Twitter. I have a decent following on google and facebook but I just can't seem to get my twitter followers up! - I barely get a few followers a month. Granted, I mainly tweet about medical school and medical board exam related stuff (maybe it's a very small niche)?



I'd appreciate any help.



Thanks!