Spotting @ 4 weeks

Im 4 weeks 4 days today. I found out i was pregnant on friday. Took a clear blue. Clear blue digital and a tescos own. All positive. I was 2 days late at that point. Booked midwife appointment for 19th July. Saturday i got light brown discharge type spotting and had slight cramping. From what i read i assumed this was implantation. Tried not to panic. Nothing sunday or all day monday. Monday about 10.30pm when i went to the loo i wiped and there was bright red blood and a small clot. Nothing else. No cramping at all. I put pantyliner in and had nothing else until today when i had a light amount of light brown discharge again. Took another clear blue digital and normal clear blue. Both positive and stronger than before. Digital now says 3-4 weeks as oppose to 1-2 it said fri. So confused and worried. Thinking if it carries on im going to push for an early scan at 6 weeks. Anyone experience anything similar? Thanks x