I think if you don't temp already then it's worth doing in conjunction with the OPKs as then you know for sure when you ovulated.
There are lots of things you can do to help things along; using certain supplements can help balance hormones or keep them balanced and aid in the production of fertile cm, sperm-friendly lube is good if you struggle in the ewcm department, as is drinking plenty of water. Eating Brazil nuts daily (1-2, but can be increased to 4-5 during lp, but don't overdo it as they contain huge amounts of selenium) can help increase progesterone, red clover and high dose vitamin E are meant to help thicken uterine lining, pumpkin seeds, sesame seeds, almonds, dark leafy greens and avoiding simple sugars all help keep hormones balanced, can help increase oestrogen and progesterone. Exercise is obviously essential for good blood flow, but don't overdo exercise as you don't want your body fat percentage to be too low. Fertility yoga is said to be good, acupuncture can help blood circulation to your uterus and keep you relaxed (which will lower cortisol levels, important for good progesterone levels), reflexology is also meant to be good. Raspberry leaf tea during your follicular phase is good to keep a toned uterus and help build lining, but don't drink it during your lp. Extra B vitamins won't hurt also.
Personally I now use B complex, extra B6, extra vitamin E and prenatal multivitamins throughout, I use raspberry leaf tea, red clover and evening primrose oil from the start of af to ovulation to aid fertile cm and hopefully thicken my lining as we discovered it's too thin.
Depending on how old you are, you may want to ask for some bloods to make sure hormones are all good, and a scan to make sure your reproductive system is fine. Ten months seems like a long time but it can take a while to conceive, however if you conceived your first two children quite quickly and easily and if you haven't used a hormonal contraceptive long term before ttc then I think I'd be inclined to ask for some basic checks just to ensure all is looking good, just for some reassurance. I'm not saying there's anything wrong of course! But sometimes there may be things without symptoms or minimal symptoms that can be easily corrected. For instance, I had a polyp I didn't know I had, it removed itself thankfully and after a scan I now know I don't have anymore but something like this can give no symptoms and can seriously hinder any attempts. So I think it's always worth checking these things out if it's been a while, especially if conceiving your other children was easily done
