My employer is denying me FMLA for my baby

I took FMLA for the birth of my son. In May 2007 (5 months pregnant) I was put on bedrest due to having preterm labor. I was off on FMLA from May 14 until October 8th 2007. Around August 1st I recieved a letter from my employer stating that if I didn't return to work by August 10th I would be terminated. I was still pregnant so I called and they said it was just a formality to let me know my FMLA was about to expire. That I had to call in each week with updates and that it was just a leave of absence instead of FMLA. That my job was no longer protected. My son was born on August 23 and only has one kidney. On the 1st of May 2008 I asked for FMLA papers for my son "just in case something happens with my son" (He has an appointment with his Nephrologist in June) I was informed that I wasn't eligible for it because I used twice as much time allowed for FMLA. That they couldn't tell me when I would be eligible until October. I just want to know if you can use too much time like they said I did and if there is anything I can do?