3 days late and ???? Test results

Bethan • Married 4yrs with 4yr old Boy. Pregnant with TWINS!!! after TTC 2 months. Very nervous about this time after awful pregnancy and terrible labour & birth.

1 day late BFN, 2 days late BFN. Took 1 this morning but nothing showed up, however a few late I went to bathroom remembering the stick, went to put it in the bin and saw this.

Is it a flash positive after a few hours. I only had a pack of 3. Can't get anymore till I go to work in 2 days as mother in law with me and really really don't won't her seeing me buy a test. Any advice?