I finished my 2 rounds of interview with a company 'A' on Friday evening. First one was telephonic and second was on-site. After on-site interview, I had sent out a 'thank you' email to the HR. After 15 minutes, he confirmed me via reply email that technical team was pleased with my skill set and wants me to be on board. He also mentioned key things about salary, contract period (X months) and position. He mentioned that formal letter would be issued on Monday shortly thereafter. I asked for few more dollars besides the salary offered. Monday has passed by and I still didn't receive any reply from the company HR and today is Tuesday.
Do I need to worry anything about the offer? Did I do any mistake of asking few more dollars than what I offered.