Hey, I am not sure whether you are more fertile after having a baby, but I do know that just because you were trying for a baby for 2yrs with your first doesnt mean it would take that long again. Things just happen sometimes. Considering you have said you had ew cm, the most fertile cm, there is a good chance you are pregnant again. I am taking it from your dates your a/f isnt late yet?
You havent said whether you would be happy about having another baby, but my advice would be as soon as you can test do it and see a doctor as soon as you can to get advice on the meds your on. If you arent wanting another baby your best option is to get yourself some b/c!!
Wishing you luck and I hope everything works out the way you want it too.