Well, possibly if it was a very high dose, then there could have been some effects then and if your problems only started after using this, then this sounds probable. Normally though, inhaled steroids such as asthma inhalers do not normally have systemic effects, but may be nasal sprays are different.
Anyway, if you are not taking this anymore, then I would just wait and see what happens to your periods and try and let them resolve naturally. Your body should adjust in time. If not then go and see your doc.
However, can I strongly suggest that you do not use a steroid spray for hay fever again? There are plenty of natural, safe and very effective alternative treatments around now that do actually work very well. These include acupuncture, homeopathy and herbal medicinal products.
As a young adult in my 20's, I developed asthma suddenly and severely as a result of other allergies. I was put on ventolin and a steroid inhaler by my doc at the time, as I was always getting bronchitis after a cold. This continued for some years, until I started getting a hoarse voice from taking the steroids, so I decided to stop. A friend of mine then introduced me to acupuncture and after only two treatments, my breathing and health generally were vastly improved. After a course of about 8 treatments I had no problems. Not long after that, I discovered homeopathy and now use a mixture of homeopathy and acupuncture to resolve any health problems that occur for me. No more steroids or ventolin or asthma for that matter.