Hi teacakes
At your baby's 8 month check-up you should be asked to fill out the Edinburgh questionnaire again, which Healthvisitors use as an indicator of PND. If in doubt, you could always ask your hv if you could do it a few weeks sooner, and therefore chat to her about it now. In preparation, it is worth thinking how you feel on a bad day, as you should use that as your guide to answering the questions, rather than how you feel on the day of the visit, which may be more happier, once you have a visitor in the house admiring your beautiful baby and chatting to you. I certainly made that mistake and so didn't get help with PND after ds1. I didn't make the same mistake second time.
The questionnaire asks questions like: do you cry - all day, sometimes, rarely . . .can't remember any more myself at the moment. Others might help.
Being a new mum and giving up work can definitely be a lonely experience with or without PND, as you can lose work colleagues, and lose contact with friends who work all day, or whose kids are of different ages to yours. I found it really really hard to meet other mums, who had not already formed close links with other mums, and found I had to persist in trying any different groups going to increase the range of people I was meeting. I also found that I missed my supportive but distant family loads too. Until you have a baby, you don't realise how far away they are!
Joining a gym for an occasional evening workout made me feel human again rather than 'just' a mum with leaky boobs and arms full of nappy bags! You also get to finish whole sentences, and to make eye contact with someone when talking to them! And MN is great for discovering other people who share your interests and remind you how to be you.
PND has many symptoms but generally linked to a feeling of blackness, hopelessness that hangs around horribly.
Do hope that you have a good HV. Let us know how you get on.