Me and my partner have been trying for 19 months I'm 21 he's 26 we have both been checked I have brought books that garentee pregnancy in 2 months but still nothing I am calculating my day doing the right positions I'm runnng out of ideas and its getting to the point that I'm getting depessed over it so please anyone have any ideas

Your first mistake was buying a book that makes outlandish guarantees no book can possibly guarantee..

Second.. have you been to an OB/GYN and have you BOTH been tested to determine where the problem is? And if there is actually a problem.