day 52 of cycle, two neg. pregnancy tests and no symptoms

Medea • 42 years old, TTC for the first time ever! Curious to see how long it takes! To date, have had 3 failed IUIs...
Hi. I'm now on day 52 of my cycle. I took home pregnancy tests on day #42 and again on #49. So far, both tests have been negative. My RE isn't overly concerned and told me to contact them if my period doesn't show for 3 months... My acupuncturist says I have liver chi stagnation and prescribed me some herbs... I'd really like to know what is going on and I'm disappointed that my RE isn't more concerned. Is it thyroid? Am I peri menopausal? Could I be pregnant and just have really low HCG? I'm 42, have been TTC for the first time for the past 16 months, already spent a small fortune on three failed IUIs... Should I try to find a naturopath? I think that if I'm not getting my period there must be a reason... and oh yeah, I have a history of cysts. Meanwhile, every woman around me is extremely pregnant and it makes me just want to cry. (I had a job interview today and the woman who interviewed me was 8+ months pregnant.) While I'm happy for everyone, I can't help but wonder if I'll ever get pregnant...