Isolation period wrong

[Tinysnickers]

I got a positive PCR result last night on a postal PCR.
Have been positive on LF and had symptoms for ages but got negative results on drive in PCR like many others in the SW.

have just filled in the form linked by test and trace and its given me an isolation period of 12 days. I don't understand why, I definitely entered my dates correctly.
Online it clearly states 10days starting the day after symptoms began. Their dates make 12 days starting day after symptoms began.
I've already been staying at home, essentially out of goodwill rather than legal obligation (because their stupid pcrs were false negatives I didn't have to) , I really don't want to end up isolating an extra 2 days when I'm not even contagious any more.
Feeling quite cross about the whole thing now.

First day is day zero (!) but yes their system is inflexible for when you end up with a late positive . Tbh they don't check physically so you could ignore, I have t as too scared of fine even though it's been more than ten days for me too due to same reason (negative pcrs initially).

I don't see how the late positive should matter. Surely 10 days from day 0 of symptoms remains 10 days whatever date you had the test?!? The website allows you to test up to day 8 (which I did- as well as day zero and day 4!!) so they should accept that.
I'm generally a law abiding person and have stuck to their rules throughout but this really makes me cross.

I think you're right. Especially as I've been in a similar situation. Symptoms started on Friday, didn't actually get a positive PCR until Tuesday. Inputted this into system and for me it counted Friday as day 0

My DD's first test was in readable and we had to re do it (both postal) so we didn't get a positive result until day 6, they back dates her isolation period to first day of symptoms. I wouldn't have accepted it if they had tried starting it from the positive test day. It has been hard enough for her doing the 10 days isolation

Maybe they will backdate when I speak to someone but they've not called me yet.

If there is a long gap between the start of symptoms and when you have a positive PCR test, there is a complicated algorithm that they use which means they don't count the start of symptoms as day 0. Or at least there used to be.

They really should make that clear when you book a test for day 7/8. Because the website very clearly says 10 days from symptom unless high temp continues.
But if I had known the positive result would mean an extra 2 days isolating I would have just gone with the pcrs and done my 10 days.

Gone with the lateral flows I mean.