I believe it is based off your last period. Or most doctors do. For example, my period was due today (no show ) so I am 4 weeks today. My last period was 4 weeks ago today. Does that make sense? Some ladies have longer cycles and go by o day too.
That does make sense. But what's confusing me is that the same app that shows me I'm 4w 2d is displaying info for week five. Does that mean I'm in week five? It doesn't make that big of a difference... my mom asked me last night how far along I am and I said four weeks but the second-guessed myself.
You are in week 5. From 0 days (start of lmp) tp 6 days you are in week 1 - the first week of pregnancy even if not pregnant. From 7days-13 you are in week 2, 14-20days is week 3 and so on. So, at 4 weeks 2 days you are in week 5 of your pregnancy. It is the same as saying before your 1st birthday you are in the first year of your life.
It's because some docs and calculators are using Naegle's Rule, some a stright LMP, and some Nichol's rule to determine "due date." I actually prefer a provider who will use Nichol's Rule. I would encourge you to take the latest date possible. So many moms are needlessly pressured for inductions and testing and procedures which are not needed because of the date. 4 days might not seem like a lot right now - but it could be a huge deal down the road. I had a client lst month pressured into an induction (bullied is a better word) because she was 41 weeks. In reality she HAD an early ultrasound which put her date 5 days later (that's almost a whole week - putting her nowhere near completeing 41 weeks) and they told if it wasn't more than 5 days they refused to change it. She did not respond well to the induction (She had a very low Bishop's score) and they deemed her "failure to progress" and insisted on a c-section. You WANT those extra days! Especially if you do not want to be induced.
Homebirthing, breastfeeding, sling wearing, cloth diapering momma to 3 girls ages 7 and 6 year old twins and peanut #4 due sometime in late September