All good questions. If you are under age 35, I would start things off by going on
clomid and if the clomid regulates your periods and causes you to ovulate more regularly give the clomid 3-4 months. If you are not pregnant after four regular ovulations on clomid, then have your partner get a semenanalysis and even think then about a hysterosalpingogram to check your fallopian tubes. There is nothing wrong with doing a sperm count and a hysterosalpingogram right of the bat, but I am not sure this will be necessary.