Waiting to tractor second child.

Karen • Trying for our second child.
Our son is 5. We had trouble conceiving the first time due to DH low and slow sperm count. It took us 15 months to conceive last time. After 12 months we were worried so we went to get him checked out and that's when we got the news. They gave us suggestions and one was to start him on vitamins. 3 months later we were pregnant. I am afraid we will have trouble this time around as well. DH is already on vitamins. I beginning to track my cycles and ovulation now to ttc in April/May. I am just nervous and needed to vent. Has anyone else been in a similar situation?