It sounds like stress can cause mild elevations in prolactin, and it often occurs in concert with hypothyroidism.
"Stressant conditions might be per se able to increase PRL plasma levels in most of the patients with hypothalamic amenorrhea, although in a certain part of them, PRL levels are normal or at the lower level of normality.
PRL excess can be due also to an abnormal thyroid function. In general, both PRL excess and thyroid dysfunction are affective in inducing an impairment up to the blockade of the ovarian cycle. On such basis, it becomes evident that if PRL or thyroid disturbances are present, they have to be eliminated.
Hypothyroidism is frequent, and it is characterized by the elevation of both TSH and PRL plasma levels. It is relevant to evaluate both hormones together since hyperprolactinemia together with a normal TSH levels (i.e., below 4.5 μIU/ml) is highly suggestive for a stress-induced hyperprolactinemia (with PRL below 30–35 ng/ml) or for a pituitary micro adenoma (with PRL above 40 ng/ml)."
Frontiers in gynecological endocrinology. Volume 3, Ovarian function and reproduction - from needs to possibilities /: Pharmacological and Integrative Treatment of Stress-Induced Hypothalamic Amenorrhea