Possible Positive?

[REW15]

Hi
So my period ended around the 14th/15th December and we had unprotected sex the day after. I have felt quite off it the past few days so thought I would take a pregnancy test even though I did believe it was quite rare to get pregnant straight after your period. I took a Tesco blue dye pregnancy test which I have heard can be quite temperamental. It seems to be showing a faint positive but I’m unsure if it is an evap line? Any ideas? I do already have a daughter so it would be lovely for her to have a sibling!
Any help would be much appreciated
Thanks

I know a lot of us on here have had bad evap lines on the Tesco tests. I'd say re test with a different brand as I personally can't trust them after them giving me very blue lines when I literally cane on my period several hours later, I hope yours is a true line though but I'd hey a pink dye test xx