Was this implantation bleeding?

Hi everyone! Was just reading someone's post about implantation bleeding and I'm wondering if that's what happened to me. On the 21st I got my iud out and I think I was on my period because before it was out I had period cramps. Then the 21st to the 24th I had constant light spotting. We then ttc a few times and then I had light spotting again for 2 days. It was a light brown discharge sometimes string like and then it was completely gone. Since then I've been getting cramps (light) nauseous and past few days constipation. Could I have already gotten pregnant!?!?