Pregnant already?

Hello everyone. So this is my first time posting and I’m hoping to get some insight?! HELP!!!! Ok so I found out I was pregnant right after Christmas. As odd as it sounds I was having symptoms hard nipples that were moist morning sickness (throwing up and all) my sense of smell changed. It didn’t appear on any pregnancy tests so I told my obgyn then did a blood test and that is when they called confirming but they wanted me to go again in 2 days as my levels were really low. I did get the second test but I already knew I was miscarrying because of my cramping I was having. It appeared that I had a chemical pregnancy they determined this because it was so early in pregnancy there was no sac or fetus at all even appearing Anyhow everything was out of my body by 7th of January. Anyhow I did not go back on bc cause I wanna know why this is happening it is my 2nd miscarriage. Now this last week I have been experiencing similar symptoms frequent urination, nauseous, hard nipples. FYI my nipples never get hard 😔 even during a period. So I’m wondering is this maybe in my head is it too soon to be pregnant again is it impossible to have symptoms this early ?