Pregnancy affecting sex?

Hi ladies I've never posted here before as I have just joined the community. I recently stopped taking the pill (last month) after being on it for 10 years. We are trying to conceive and I must admit it's been fun! The past 2 times we have had sex I have been incredibly tuned on and ready, but had an extremely difficult time trying to climax. This has never happened before. I believe I was supposed to get my period this week, but it hasn't come yet. Has anyone else experienced this? I want sex all the time, but it it becoming increasingly more difficult to achieve the big O. Thanks for listening :)