It's impossible for us to tell you whether your pain is just the normal process of getting used to riding, or a result of poor position on the bike, or because the saddle doesn't suit you.
One clue would be where the pain is felt. Is it over your sit bones? If so, probably nothing to worry about, it will wear off. If it is the soft tissue between your legs that hurts, either your position is wrong - your weight may be being borne by the narrow part of the saddle, instead of the wider part at the back - or the saddle isn't right for you. It may take you a while to work out which.
As for the rest, ride as much as you feel able. I don't think 30-45 minute rides are going to do you any harm.