Fertility

Me and my husband have been together for 3 years and we just recently gotten married though we are not ready for a baby that's all that's been on my mind! I never ever have a regular period my dr told me I might have to be put in fertility pills to conceive but all that goes through my head is I can't have kids! I am not on bc and use no other form of conception it's just if it happens it happens! But my mind still goes 100 mph on the what ifs is that normal?