Open Question: Would my AIG mess up my tax return?

So..this year all my friends convinced me to do my taxes by my self.. they said it was very easy and you save a lot of money. Well I did my taxes through H&R Block online, at first when I was doing my federal taxes it had given me a different number then..when I did my State taxes. At the begining it said I was getting money back because I didnt make that much money. After the interview thing..I put my Pin # as my AGI and Pin # (dont know why i did this SMH) but yeah so thats my thing.. I put my pin in both AGI and pin..so after that it wouldnt let me go back to change it because i filed my federal taxes.. i still havent faxed my state taxes because now it says I have to pay about $500.. so basically my question is..what should I do.. should i contact IRS and let them know? or wait till i get my refund and just pay for it? I just find it weird how first it said I was going to get a refund and after i put my pin as my AGI now it says I owe money. HELPPP!! Thanks :)