What vitamins to take to prepare for conception ? Ttc

I turned 30 in April and will be 31 soon .I am planning on ttc . I've never tried before and I'm worried now because they say all types of things about concieving in your thirties. Also I know after I ovulate my period is only 7 days after so I've started to asking vitex In hopes of lenghtening that because I read you need ten days for egg to implant. I think I almost concieved once. My nipples have always been skin color almost exactly. We had sex on ovulation or maybe it was a few days before m I can't remember no more. This was like three years ago . Anyways my nipples changed color . They were no longer er pinkish beige but brownish . I had my period a few days late and I took a test and it was I'd say inconclusive as it was 1 & 1/ 2 line. Then a few days after git my period and my nipples lightened up a bit but not are a brownish pink . And have never gone back to my beige ish pink color.this is the only time my nipples have ever changed color. Anyways please suggust vitamins etc...