Irregular periods & pregnancy

I've experienced irregular periods before where it may come for a few months and then stop for a month or 2 but never 4 months... Has anyone ever experienced this ? Has anyone ever been pregnant and not had not one symptom ? If I am pregnant I have NO symptoms besides a missed period.. Is that even possible to be so far alon with no symptoms ... My HPT SAYS Negative now I'm just waitingn for my blood test from the doctor ... Advice ladies!