What do you guys think?!

My first born is only 3 months and I’ve had a vvvvfp these last few days... it isn’t getting darker yet and I’m 3 days until AF... but I’ve had little cramps in my uterus this last week, headache, and little electric twinges in my uterus... but no sore boobs like with my first... do y’all think I could be pregnant? If so why are my hcg levels still so low after a few days even? Then again I haven’t retested with a frer since then... I’m saving a clear blue Digital to take on the day of my missed period. We actually wanted another baby soon after first.