Possibly pregnant again?

I'm going to post here because I have a ten week old baby boy and been with you ladies for the past year almost and need a little advice lol... I want to start by saying please no negativity I wasnt actively trying for this to happen if this is the case, I desperately have been trying to get my body back to normal since having my baby and letting myself heal(I had such a rough pregnancy) but on the other hand I'm married with two children and a job so this is not awful if I am...

I've only had sex with my husband 3 times since my 6 week check up, he pulled out each time(I know not the best protection) and we did wait the full 6 weeks before having sex. I still havent had a period since having the baby and I'm currently 10 weeks postpartum(not breastfeeding, switched to formula at 3 weeks).

Last night and today I have taken two different pregnancy test just to check, both of these were taken at different times and within the time frame. Do these test look invalid to you all or am I pregnant again? What's the chances of having two invalid test? Is it possible to hav

e left over hcg left over after all this time?