My friend is bleedin thick clumps of blood and she just had her period.. whats going on? (miscarriage?)?

hi my friend is 18 and she said she just got off her period 2weeks ago but now she's bleeding down there again and it's very thick blood... yes she's ually active.. dont know if she safe.. but she really wants to know whats going on and what should she do.... she wants to go to the clinic but she's afraid her mother is goin to find out she went... so can you tell us whats wronge or what she needs to do? please and thank you.... she will be reading alonge and is already hurt of what's happening so please leave out all the bad comments