Conflicting dermatologist diagnoses - Androgenic Alopecia or Chronic Telogen Effluvium?

You need to consult with a dermatologist who specializes in hair loss. Your family history does not really matter much and does not sway me either way. An up close examination of the scalp is what is needed. Your blood tests are nice to have and are important - but also do not sway the diagnosis. Androgenetic alopecia in women is associated with reduction in hair density with evidence of follicular miniaturization (if far enough along).The hair loss can be diffuse in some women and the frontal zones often have a slightly greater degree of thinning than the back, but the back certainly can be thin and so can the sides. Androgenetic alopecia gives increased shedding of hair in early stages which complicates things sometimes and leads to the misdiagnosis of TE. If there is any uncertainty, get a biopsy of the scalp. If read by a dermatopathologist who specializes in hair samples, the two can be distinguished. You may of course, have both conditions as many women do.

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I think your next step is to see a
hair restoration specialist to obtain a bit more history in terms of onset and
progression of hair loss.  But more
importantly, you need a microscopic evaluation to assess distribution of hair
loss, document miniaturization and take a good look at the scalp itself.  On occasion a scalp biopsy may be necessary.

Female pattern hair loss or genetic alopecia is the most common reason of hair loss in women and it is more common than it is thought to be. 25% of the women at the ages of 35-40, 50% of the women at the ages above 40 suffer from hair loss. 20% of the women with hair loss have a positive relative who suffered/is suffering from hair loss. Other reasons of hair loss are: Hypo- and hyper-tiroidism (hair loss may be one of the early signs of thyroid dysfunction, and hair loss stops after treatment); polycystic ovarian syndrome (an inherited ovarian disease, seen in 10% of the women during adulthood); pregnancy-related hormonal changes (temporary hair loss which can be seen during pregnancy stops after birth)..

The reason of the hair loss may related with factors other than genetic like connective tissue disorders, stress, anemia, lupus, medications, hormonal and seasonal changes, nutritional problems, severe diets, bulimia, protein/calorie deficiency, zinc and essential amino-acid deficiency, mal-absorption (intestinal and digestive problems), A-vitamin excess, general anesthesia, affective mood disorders.

Drugs that may cause hair loss in woman 

Anti-coagulants such as warfarin and heparin  
Epilepsy drugs, especially dilantin
Gout drugs, allopurinol and colchicum
Antihypertensive drugs, diuretics, beta blockers.... etc

So you have to have a full exam with an hair surgeon, internalist and/or endocrinologist to find out any reason for hair loss.

I can imagine your frustration at getting such disparate diagnoses.  Did anything change between the two visits? 
Assuming you don't have PCOS, a full evaluation by a dermatologist who specializes in hair loss (not all do) that includes a biopsy of your scalp would be beneficial.

See a Doctor who specializes in hair loss and can perform a digital microscopic scalp analysis for you.  These two types of hair loss are very different in their presentation.  
Androgenetic alopecia is characterized by miniaturized hair which you will clearly see under the microscope.
Telogen Effluvium causes hairs to fall out and you will see empty follicles instead.
Make sure you see someone who can show your scalp up on a big screen so you can see for yourself too.

A biiopsy in the hands of a good dermatologist will tell you possibly what is your diagnosis with some certainty