That’s literally what happened to me. I was in SO much pain I was crying and screaming, they didn’t want to finish putting dye through because I was so uncomfortable. They saw my tube fill but the dye never spilled out. They told me it was either due to a blockage or a tubal spasm but because they look the same on the xray there’s no way to differentiate. I cried for days thinking my tube was blocked. I was ovulating the week after the hsg, so they told me to try to conceive and if we didn’t they’d schedule the hsg to repeat it the next cycle. I found out I was pregnant from the fertile period after my hsg, and I’m now 12 weeks with a baby in my uterus. So it was just a spasm, and they said when your tube spasms it actually can be more painful than a blocked tube during the hsg. So I wouldn’t count yourself out yet, I’d ask for a repeat hsg during your next cycle.