Not conceiving after 3 months of trial is not a matter to be concerned about a lot. It does take time and one has to be patient. You can try a calender method to get to the exact dates of your expected ovulation and can increase the sex frequency during that period. The other modern way to keep observing your follicle on a USG machine and to make contact exactly around the date when it is supposed to ovulate. IN that case you will have a better chance to pregnancy
. But 3 months is not a time to panic and can keep trying. Mild spotting after the end of period is again no big concern and mostly it doesnt repeat.
Hope I am able to solve your concerns