Dear Sir, I Had A Sex With My Wife Before

dear Sir, I had a sex with my wife before a week ago without any precaution and I come down inside her...and now she have a itching problem and she is pissing more than 10 times in a day...So, Sir please let me know that is there any chance of pregnancy...if Yes please let me know about some medicines that how should we avoid that...Please reply me soon as its really serious for us as we are not in conditions to have a baby now...