About august last year I noticed I started getting unusual discharge. It was about a week before I got my period and it smelt a little bit funny compared to usual, was a bit uncomfortable down there and the discharge was a bit lumpy and green/yellowish. It started at a time when I was under stress so I assumed it was from that however decided to monitor it. I've noticed it only goes like this a week or so before I'm due for my period and isn't completely green/yellow, the undertones are and it's not like that ever time I wipe down there at that time. I started taking probiotics about 2-3 months after I first noticed and since then it's not as bad it doesn't smell and there is no discomfort, itching or burning. I've noticed the colour isn't as bright as the first few times but is still noticeable and occasionally a bit brighter in colour. I've been wanting to get it checked out but I'm a bit scared and decided to do my research beforehand. What could be wrong ?  Should i be concerned?