hey cassandra, firstly, yes semen is carried around by the female for about that duration after the first courting session, or concievmnet! Secondly, i suggest if you really want fry, you have to be patient, i know that sounds crappy, but another thing i will suggest is, that you put some more objects into the seperate breeding tank! Vegetation for the fry to esacpe and hide from the parent. DOnt depend on the rubbish that the companys provide us with as it is pretty ineffective and low budget! I belive that The fry must adapt to survival of the fittest as soon as possible, and i find that using breeding nets are more destructive than usefullll. I find its more likely to stress my females out rather than protecting the fry. Ive even had females die from stress... I now keep things really natural in my hexhagonal tank. I started off really basic with about 6 guppys. " males 4 female. That was about a yeaqr ago now. I now have 40 odd coloufull family/breeding machine. I dont bother to remove pregnant females anymore as i find that if i leave them in the tank to labour, most of the fry will be eaten to keep my numbers down. I have recently purchased 5 silver, and dalmation Mollies, and two of them have had fry in the tank aswell.
My point is, leaving your tank to grow by itself and mature with time will always be better in the long run. Its less effort for you, aand less stress for the fish, no matter what all these " experts" say about changing at least 20% of your tanks water each dayetc. Its all to hampy pampy! It takes away the whole enjoyment of having fish.
Let biodiversity do the work for you! Add snails, and lots of rooting aquairium plants to later save money, and let things thrive. I bet it works.
hope any of that helps!