Alternatively, you can suggest that you speak when you pick up your child from school that day. This is the least intrusive way to talk to the teacher. Make a date. Many teachers are working parents themselves, and are sensitive to the demands on your time. Most try to make themselves available either before or after school, or during lunch.
Many schools are now online.
If your child's is, you can e-mail the teacher during the day. Some teachers will give you this information with the understanding that you contact them at home only if it's an emergency. Assure the teacher that you'll keep the information private. Help out in class. Volunteer to be a class parent if you have the time.