Birth classes

What do you guys think of the birthing classes if you ladies have already taken them? My sister in law was telling me I should for sure take them because their very helpful but the thing is I already missed one of the classes from the series (there is 4 of them in the series) and they start at a time where my husband is still at work.. Idk what to do, if I should go on my own or if it's not really worth it.. Idk!?