going back to a previous section of the ACT

I recently just took the ACT. I finished the English section. The proctor called time. And then we started the math section and if I would get stuck on a question I would put a little slash mark by it to know to go back to it at the end. I only left one of the math problems blank. But I forgot about it and didn’t remember until I was starting the science portion, two sections later. I didn’t go back to the actual blank question in the booklet. I just put a random bubble in for the math problem on my answer sheet and I erased the slash mark. I only found out today that after each section is finished, proctors go around and count how many you didn’t fill in. That way, when your test is being scored, they will know if you went back and cheated. But I didn’t go to the question I left blank in the booklet. I just filled in a random answer. And I’m terrified that I will get caught. It’s just one question though. Do you think the scoring people will notice or even see it?