I'm not sure if you're aware of this or not, but it takes the average healthy couple about a year to conceive naturally. Even if you're "doing everything right." But I know that time that you're trying feels like an ETERNITY! It took us SEVEN years of ttc!! That was horrendous!! :) Finally we were able to get pregnant thanks to IVF. But chances are, you won't need to do that. If you want to put your mid at ease, you can definitely go see a doctor and they can do a blood test work up on you. Turns out I had PCOS and hypothyroid which both played a part. And my husband had low sperm count. And i Have some other health issues. Anyway, there MIGHT be something else going on with you, but you won't k now unless you go get checked out by a good doctor. BEST OF LUCK to you!!
it can take a perfectly healthy couple at least a year to conceive naturally, so you've not really been trying that long...even though it feels like it. TTC does cause stress to both you and your partner, and this can mess up a woman's cycles.....hence you would start getting irregular periods. Have you been to see a doctor? I would say, go see a doctor and make sure that everything is okay in your reproductive department.
Have you tried using OPK's? You need to be having sex around the time of ovulation (your most fertile time) to increase chances of conceiving. You can also track things like your basil body temperature (BBT) and cervical mucous and cervical position to figure where abouts you are in your cycle each month.
have you been to see your doctor? they can rule out any conditions that might be preventing you from getting pregnant. also, do you know for sure that you are ovulating at that time? you can buy an ovulation predictor kit (my doctor highly recommends them) to help you determine when you are most fertile.
also, if you have a need for lubrication during sex be mindful of the brand you are using; some are not sperm/baby-making friendly. try pre-seed -- there are other conception friendly brands but i dont' know the names.