Advice please

I had a miscarriage back in August so really can't help worrying about things. I took a test on the 20th January and was negative. Decided to do another yesterday the 21st and got a faint positive. Also got a faint positive again today. Is this normal? And how long till I get a strong positive? my other pregnancies I only found out when I was further on. According to glow I'm currently 4 weeks and 4 days. Thank you