TTC with my 2nd Baby

I been trying to conceive with baby #2 but no luck yet. I have a 3 yr old son is asking for a baby sister, so we been trying for over 9 months. One time I took a pregnancy test and thought I will have a BFP but noooo I just had PMS instead of pregnancy symptoms, I was so disappointed. Idk why it’s so hard to get pregnant again with baby #2. I thought most women gets fertile after the 1st kid, well not me I’m having a hard time trying to conceive. So I just leave it up to the good lord above when he ready for me to have baby #2🙏🏽🙏🏽🙏🏽