My estrogen was low on the reference range but still within the margins, can I still consider it an issue even though my obgyn doesn't think so?

Difficult. Hormone levels are very hard to interpret, as they are are quite variable throughout the day and from patient to patient. The interpretation is quite dependent on your clinical situation. If you are not getting a good explanation, a reproductive endocrinologist could give you a more expert opinion than a generalist ob/gyn.
Sex hormones. Low in the range could be perfectly ok, all depends the time of the cycle in which was taken, your age and at what time the test was done.