Some astrologers would count 3 planets in a sign or house as a stellium Others would say you need four or more to qualify. Either way, you do have a 7th house emphasis.
The 7th is the house of marriage, permanent relationships, various sorts of long-term partnerships, and also opponents and open enemies. I guess it doesn't take much to turn longer-term partners into enemies when a relationship sours!
You probably have a big focus on being part of a committed couple, whether you are actually in a relationship now or not. Saturn in the 7th house and Capricorn on the cusp of the 7th can indicate disappointments and delays, but your Saturn actually isn't badly aspected, as it sextiles your sun. It may be that you will find your dream partner later in life or that this person will be older than you-- or simply mature for their age. Saturn can show where you feel inadequate or "not good enough"-- if this happens to you in the Relationship Department, just realize that how you feel is not always an accurate barometer of your true worth and attractiveness.
With both Venus, Mars, and your north node of personal growth in Aquarius, and your moon in Sagittarius, you probably need a fair bit of emotional space in a relationship-- despite your Cancer rising. Cancer is such a sensitive sign that it is very easily hurt. When this happens, it is liable to retreat behind its shell. I think this makes sense, given Capricorn on the DC, which symbolizes older people. Someone who stays out of circulation for fear of getting hurt again is unlikely to put herself into situations where she could meet someone new.
Fortunately your Sagittarius moon needs to get out of the house, so this should help you in your socializing.
Mars in the 7th can indicate a certain feistiness-- maybe a willingness to get into an argument with an "opponent" when tact would be the better course of action. But this placement could also give you a lot of enjoyment out of partner-type sports such as tennis, racquet ball, &c.