Lower leg pain

snowdrops

Hello,
I've just started running outdoors again (on grass) gradually over the last few weeks I've built my miles upto 6. I did a run on Sunday and my legs felt fine although yesterday morning (and still now!) the outside of my right leg just up from my ankle bone up towards half way up my lower leg it feels sort of bruised crossed with really tightness - similar feeling so shin splints. I'm really annoyed as I was so happy being able to run outdoors again and start getting a base for when I pick up my training for the London Marathon next year :-( I am not going running tonight as planned as I don't want to make the injury worse only I don't know what it could be - inflamed or just tight muscles? It hurts when I point my toes and turn my foot out but not pain like a tear more tightness pain. I'd be really grateful to hear from anyone who has had similar or knows what it could be and how to treat it and when to start my running again!!!
Thank you Kate :-)