Three days late

So I’m three days late I’ve done some pregnancy test I’ve had two negative and one very light positive I tested again today I swear I can see a line but I aren’t that sure I’ve just got my cycle back on track after having my baby boy who’s nearly four months I’ve had around three cycles since he’s been born and everything was back to normal me and my husband haven’t be active trying but we don’t use contraception I’m having clear stretchy discharge a lot of it I’ve been feeling sick in the morning but If I was pregnant it make me four weeks pregnant so wouldn’t the line be a good shade to see it was with my daughter and son anyone experienced this or got any advice