Postpartum Depression?

My baby is almost 4 months now and for the last few weeks I have felt down. I will randomly feel regret of having her, like I'm not looking forward to the future of raising her and like I'm a bad mom for wishing I hadn't had her.. I don't feel the need to hold her or feed her, but I do, and I feel so fatigued and don't want to do anything, especially get up in the mornings. But other times I'm so happy and I feel so lucky to have her and I just want to hold her forever. I don't know why I'm feeling having such mixed feelings. The last few months have been rough on me, my hormones are crazy and I've been moody, sick feeling, and so tired. But she is such a perfect little girl and she's so well behaved for a 4 month old, and I love when she smiles at me. I hate myself for feeling like this. Do you think I may have PPD? Should I go see my doctor about it? Or do you think it's just hormones that will pass?