There is lots of variation in menstrual periods even in normal fertile women. Sometimes the period maybe heavy; sometimes it maybe light; sometimes there may be clots or spotting ; and sometimes there maybe more cramping than usual. These are common variants, and most fertile women don't even notice them.
Infertile women, on the other hand, obsess over every minor variation. Was the period too heavy ? Was there clotting ? Could that have been an early pregnancy which miscarried early because I lifted a heavy bucket ?
If my period has become very light , does this mean my uterine lining is too thin ? Does this mean that the embryo will not be able to implant ?
My periods are due in 2- 3days, but my breast fullness and tenderness is much more this time. Is it just PMS ? or does it suggest an early pregnancy ?
Is the spotting I get before my flow mean that I have endometriosis ?
The mind plays all kinds of games in infertile women , and since you cannot see the eggs and the sperm and the uterine lining, you worry about the only thing which you can see - your menstrual flow. You try to correlate every variation in your periods to your inability to get pregnant.
The truth is that there is little correlation between your menstrual cycle and your fertility , as long as your cycles are regular.
In any case, rather than worrying needlessly about this, the best option is to get a basic medical evaluation, to reassure yourself that all is well !