confused 😩

Soo me and my husband have been trying for another baby , I just had my son 3 months ago and we want another close in age well I had my first period after him September 1st-8th and I still haven't got it again yet 😩 I've took 3 test the first 2 was a very faint positive (2 different brands) and the 3rd one a few days later was negative and I've been having pains and that's why I took the 3rd one...idk why the first 2 was faint but the 3rd was negative ?! Has this happened to anyone else ? What could it be or mean ? 😩😭😩 help please !