I had sex the first fertile day and my husband came in me is there a chance at pregnacy I have irregular peroids?

Yes. A woman who is of child-bearing age and having intercourse has a chance of getting pregnant.
Yes. If you had intercourse around the time of ovulation there is a chance you could be pregnant. Most women ovulate 12 - 14 days before their next period, but if you have irregular periods this may not be the case. The likelihood of pregnancy with each cycle in couples with normal fertility is around 20%.
Yes there is. Intercourse with ejaculation , providing you are ovulating, is the main factor. Good swimmers from him and an egg from you = good chances!