3 days late

Charlotte

So today I have had spotting all day, only when I wipe. It’s like bright pink. Did a £1 hcg test strip and I swear down it had two lines then did a supermarket Tesco’s own and it was negative! I’ve had like a bad back now and again & a few sharp pains in my stomach but nothing as thou to say I’m coming on my period? Should I retest in the morning or shall I just go ahead and say it’s negative?!