Most thyroid nodules are benign (90-95%). Many people have thyroid nodules and are not aware of it. I was told by my doctor that 20% of 20 year old women, 30% of 30 year old women, 40% of 40 women, etc. have thyroid nodules, so it is fairly common.
Usually a fine needle biopsy (aspiration) is recommended when the nodules reach a certain size (guidelines vary, but usually they will wait until it is at least 1 cm in diameter, sometimes only if it is larger than 2 cm). Getting a biopsy does not mean it is cancer, there is still a very good chance that it is benign, but it is good to go monitor it and make sure it is benign.
The nodules may or may not have anything to do with your thyroid hormone levels -- people can have nodules and no hormone problem. Without a reference range, it is hard to tell whether your thyroid hormones are low. (Your TSH seems fine - usually less than 0.45 means hyperthyroidism and above 5 means hypothyroidism, but TSH can be "in range" and there could still be a thyroid hormone problem). Are you experiencing any symptoms of hypothyroidism or hyperthyroidism? If so, that might be something to get further testing on. Having nodules does not necessarily mean you have a thyroid hormone problem, but some women experience postpartum thyroid hormone issues, so given the timing you might want to make sure you don't have a hormone problem.
Good luck with your biopsy.
What was the reference range for the Free T4? Ranges vary from lab to lab and have to come from your own report. Was Free T4 and TSH the only blood work they did?
What, if any, symptoms do you have, other than the lump you feel when you swallow? A lot of us can feel that if our thyroid is swollen/inflamed.
I agree with Sarahjogs that doing an FNA isn't necessarily a bad thing.