Re: cyst or implantation bleeding?
Some women may have cysts, but display no symptoms. But, as far as common symptoms, here are the ones I'm aware of:
- Irregularities in the menstrual cycle
- Pelvic pain during intercourse, before or after the menstrual cycle, or just in general. It's usually a dull or mild ache, and it might occur on and off or is constant
- Feelings of fullness in the abdomen
- Breast tenderness
- Vaginal discharge of a thick, creamy consistency, or a consistency similar to egg whites
Some of these are also pregnancy symptoms, but things like nausea and breast tenderness would not show up usually until about 2-4 weeks following conception. Implantation bleeding is usually just light spotting, sometimes accompanied by light cramping. It usually occurs 4-6 days after conception, but I have heard that it can also happen 11-12 days after conception. Spotting could be anything, though...endometriosis, PCOS, cancer, or maybe something as simple as a hormone flux.
Has your girlfriend been stressing out, thinking she could be pregnant? Has she changed her diet recently, or lost a significant amount of weight? Has she begun any kind of exercise? Any of those can cause a drastic change in a woman's cycle.
If it's a huge concern, your girlfriend should see a doctor. While it might be something benign like stress or hormonal changes, it's better to get it checked out. Better safe than sorry.