hello at 45 age ( perimenopausal age ) irregular periods r common delayed periods r common at this age even without being pregnant also chance of fertile cycle & chance of pregnancy decreases at this age if similar patient cones to me I would do pervaginum examination to see the size of uterus & repeat upt if previous upt was more than 5 days ago if repeat upt is also negative & uterus is normal size i would induce her periods with meprate ( medroxyprogesterone) for 5 days & call her in 2 weeks to see if she got her periods . since this is prescription drug I would advise you to take it under medical supervision I would strongly advise you to use barrier contraception or copper T in future as although fertility rates r low at this age , pregnancy can still happen without birth control & irregular periods at this age adds to confusion & stress oral contraceptive pills r not desirable at this age because of effects on lipid profile hope this helps you