Positive pregnancy test!!

Hello,

So, I am 3 days late now. On 28th, I found some blood stains on my underwear and I thought it’s the period, but it stopped immediately.

I took a pregnancy test on 31st of Dec and it came out negative, today I took another one and this time it came positive.

I decided to take another tests in the evening, both of them came out negative as the first one.

I will definitely go the doctor to seek professional advice, but meanwhile has anyone any idea about what’s happening?