SM, I would be very shocked that someone would get gyno MONTHS after a cycle, since estrogen would have been metabolized and excreted very early on. Estrogen is metabolized at a relatively fast rate. After the majority of the estrogen is cleared early on, there is little androgen materials to aromatize into estrogen.
The androstenedione studies showing very rapid rise and equally rapid decline in androgen levels are indicative of how endogenous steroids are metabolized.
I found this interesting study:
J Clin Endocrinol Metab 1984 Jul;59(1):103-107
"The influence of dietary protein and carbohydrate on the principal oxidative biotransformations of estradiol in normal subjects."
Anderson KE, Kappas A, Conney AH, Bradlow HL, Fishman J.
Dietary protein, when substituted for carbohydrate or fat, can increase cytochrome P-450-dependent drug oxidation rates in humans. Endogenous estrogens, as well as drugs, are also metabolized by cytochrome P-450 and other enzymes in the hepatic endoplasmic reticulum. Therefore, it was of interest to determine whether variations in diet can alter the major metabolic pathways for estrogens, as assessed by radiometric methods. Eight normal men were fed a high protein diet (44% of calories as protein, and 35% as carbohydrate for 2 weeks), followed by a high carbohydrate diet (70% of calories as carbohydrate and 10% as protein) for an additional 2 weeks. The fat and total energy contents of the two diets were equal. The percent oxidation of [2-3H]estradiol, measured as 3H2O released, which is an in vivo measure of 2-hydroxylation of endogenous estrogen, was greater in all eight men during the high protein dietary period than during the high carbohydrate dietary period (44 +/- 3% and 33 +/- 3%, respectively, means +/- SE, P less than 0.005). In contrast, 16 alpha-hydroxylation of estrogen, as measured using [16 alpha-3H]estradiol, did not change significantly. Our findings demonstrate that dietary components can alter estradiol oxidation in humans and that the 2- and 16 alpha-hydroxylases for estrogen are under separate regulatory control. The influences of specific nutrients on estrogen metabolism may have potential significance for diseases in which these hormones may play a role in clinical expression.
P.S. Unfortunately this would apply to testosterone levels too.