Vaginal mucus too thick to get pregnant

Hello, I am 24, married, 1 pregnancy, and zero children. After 4 years of trying I finally conceived, which was during a period that I was going thru the worst cold of my life and taking cough meds. I ended up lossing the baby in the 10th week, with no explanation. I have not had fertility tests done but dr. said that with the fact that I have gotten pregnant and the fact that uterus looks fine there should be no problems. I have noticed for several years now, that my vaginal mucus NEVER thins out, and at some points in month it becomes clumpy and super thick. I have heard that taking cough meds. will thin out your cervical mucus, which is why I think I got pregnant in the first place, Is it possible for this mucus issue to be the real problem my husband and I are not getting pregnant and that it took 4 years of trying at all the right times of month to finally conceive? And if so, how do I treat this mucus issue so that I may be able to sustain a livable situation for sperm in my body? I don't have fertility insurance and don't want to spend millions of dollars, I just want to conceive!! If you have any information, please let me know. Also as far as odors are concerned, I have noticed a "fishy" smell since I started my period 10 years ago. It never seems to go away. I have had an STD check last year that came up fine, although I didn't tell my dr. of this smell and mucus issue because I was embarrassed. After reading some posts, I am realizing that I could have vaginitis or something like that. Could that also contribute to not be able to conceive? PLEASE HELP.