Skipped cycle and nervous thoughts

​So I completely skipped a cycle which is not like me at all. I took hpt's after being late and they were all negative or no reading at all. I have constant menstrual like cramps too. Now I'm starting to get nervous. What if I am? I haven't been on vitamins and I am on daily epilepsy meds. I almost feel like I don't belong having another child since my children are both over ten now. I feel guilty as if there's too many worries now that I didn't have with them. Anyone?