If you want to change your menstrual cycle for the next month can you start taking your new pack of pills later than normal so you can delay your period by a few more days? Answer. If your period is late this one time, this may not be a recurring problem. However, any concerns you have about your health should always be discussed with your doctor, and if you continue to have changes with your cycle or any other accompanying new signs or symptoms, it will be important to discuss this so you can continue to stay in good health. Taking prednisone too late in the evening can cause sleeplessness and insomnia, too. Make sure you also take your dose of prednisone with food, and just FYI, grapefruit juice has no effect on prednisone. Ensure that you call your medical doctor if you are experience these or any other unusual symptoms when taking any dosage of prednisone for any time period. Your doctor might change the dosage to make sure that you are taking the lowest amount that will work for you. I have been on prednisone several times and never noticed any changes or being late when I was on it, but that is not to say it couldn't happen as it mucks around with your body pretty badly! I used metronidazole gel and now my period is late. Can antibiotics affect your period there are also other things that can make your period late that amoxicillin and metronidazole for H pylori for. Not to discount anyone else's posts, after being on this drug every day of my life since 1984, I feel I'm a bit of an expert. Prednisone reduces inflammation - that's why it's used for things like arthritis, crohns, asthma, etc. How Can Prednisone Affect Your Period Even though Prednisone is considered a life-saving drug, many persons who use it have reported some adverse side effects. The benefit far outweighs the potential risks of the side effects, which depends mainly on the amount of time you are using it and the amount that is consumed.