Iron Tablets = 💩

So last week I found out I was iron deficient, no surprise it seems like everyone is these days. As my doctor requested, I started taking iron tablets. I know iron tablets are known to turn your poo black and can cause constipation but do they also make you poo more? I have gone from pooing once a day to pooing at least 4-5 times times a day. Could that be a type of constipation? I have been taking Vitamin C with my iron which is meant to help. Should I be worried? I don't see my doctor again until next week so I can't ask her. It's quite annoying more than anything considering I hate pooing at work but I can't stop it now.