Length of pregnancy and due dates?!

[Purplelilly]

I'm sorry if this is in the wrong section!

I am trying to get pregnant and hoping this month may have been the one. My cousin is almost 6 weeks pregnant and it's been 1.5 weeks since my ovulation.

With healthy babies, could we technically have our babies in the same week or so? I guess most likely we'll just be 5 weeks apart, but I've read about big variations in terms so am confussed a bit!

Yes, you could. If your cousin is 6 weeks pregnant, that is usually taken to mean she is 6 weeks from the first day of her last period. If you are 1.5 weeks since ovulation, then you are 3.5 weeks from the first day of your last period, so potentially 3.5 weeks pregnant. Weird, but you aren't actually pregnant for the first 2 weeks of your pregnancy... As term babies come between 37 and 42 weeks, there's plenty of scope for you to deliver on the same day, let alone in the same week. But given the odds, unlikely it'll be that close!
It's not an exact science and different women have different cycle lengths. You also don't know when you ovulated. It's usually based on ovulation at day 14 of a 28 day cycle, but that is 'textbook' rather than real life. Ovulation is also not the same as conception. Eggs and sperm can live for variable amounts of time inside you before the actually meeting and conception takes place. So if you happen to ovulate early in your cycle and there's spermatozoa round to fertilise then you'll 'conceive' earlier in te cycle than expected. Conversely, if you ovulate late then you'll conceive later in the cycle. All with the same last menstrual period (LMP) date. I guess this is in part why 'term' babies can have a 5 week window to be born in.
Hope you get a BFP in a few days.

Thank you very much for your explanation :) It makes sense now.

I said it as a joke to her (she doesn't know I'm trying) and she sounded angry that someone would take her thunder :/ Ah well, only time will tell and I'm sure I'll be waiting a good few more months yet!

Thanks again :)