Trying for a baby.

So my best friend has been trying for a baby with her fiancé this month.. and this is the second time shes tried, and on the 26th he came inside her and they used preseed.. and now shes getting a period like pain in the place where you usually put a heating pad when you have period cramps. Her period isnt until 9/13.. shes still fertile until 8/31.. but these pains would not be coming so soon... would they?