My period is always 28 days, since I've started lowcarbing its been off. The first month it was an entire week late, then 4 days late the next two months. When my period was late I felt pregnant also tired, bloated, achy breasts. I think the pregnancy tests are pretty accurate these days (maybe they weren't in your moms day). Don't get too freaked out. Two weeks is late enough to see a doctor about it. Also I have seen a lot of threads here that others have been late as well. Take care of yourself and try not to worry. I know easier said than done.