Is this discrimination against a pregnant woman?

[Erika O]

i've been going to my local bar for years and never had a problem. so i was there tonight and had enjoyed 4 or 5 beers with my husband while sitting at the bar in a high bar stool. my back started to hurt since i am 7 months pregnant and i have sit uncomfortably on those bar stools, so i asked the bar tender if i could bring a normal, short chair with a back over from one of the tables. he said no and told me that only tall stools were allowed at the bar itself. is that discrimination against me because i am pregnant? if i was disabled and in a wheelchair then i don't think they could tell me that i can't be by the bar, and there's not much difference between that and a person in a normal chair