that depends on the size of the company, your employee statues (pt, ft, temp ect)
Basically, the only way to have FMLA which you could use for dr's appts and such are if your company hires 50 or more employees, you've been with them for at least 12 months, with at least 1250 work hours, otherwise it's voluntary on the employer's part letting people take time off for medical reasons.
Do you work 9 to 5? I'm guessing you are since you have had to take off to goto the appts... that really is stinky that they told you that 
I usually use my PTO time or come in early/leave late to make up for the time I'm gone.
30 something y.o.
2003 - T45, L???
2005 - T50, L31
bunch of measurements between...
2011 - T60, L32
2013 - T68, L?
Posterior Fusion Sept 2014 -- T3 - L3
Post - op curve ~35